昼夜乐·冬

四月清和雨乍晴,南山当户转分明。更无柳絮因风起,惟有葵花向日倾。六王毕,四海一,蜀山兀,阿房出。覆压三百余里,隔离天日。骊山北构而西折,直走咸阳。二川溶溶,流入宫墙。五步一楼,十步一阁;廊腰缦回,檐牙高啄;各抱地势,钩心斗角。盘盘焉,囷囷焉,蜂房水涡,矗不知其几千万落。长桥卧波,未云何龙?复道行空,不霁何虹?高低冥迷,不知西东。歌台暖响,春光融融;舞殿冷袖,风雨凄凄。一日之内,一宫之间,而气候不齐。(不知乎 一作:不知其;西东 一作:东西)妃嫔媵嫱,王子皇孙,辞楼下殿,辇来于秦,朝歌夜弦,为秦宫人。明星荧荧,开妆镜也;绿云扰扰,梳晓鬟也;渭流涨腻,弃脂水也;烟斜雾横,焚椒兰也。雷霆乍惊,宫车过也;辘辘远听,杳不知其所之也。一肌一容,尽态极妍,缦立远视,而望幸焉。有不见者,三十六年。(有不见者 一作:有不得见者)燕赵之收藏,韩魏之经营,齐楚之精英,几世几年,剽掠其人,倚叠如山。一旦不能有,输来其间。鼎铛玉石,金块珠砾,弃掷逦迤,秦人视之,亦不甚惜。嗟乎!一人之心,千万人之心也。秦爱纷奢,人亦念其家。奈何取之尽锱铢,用之如泥沙!使负栋之柱,多于南亩之农夫;架梁之椽,多于机上之工女;钉头磷磷,多于在庾之粟粒;瓦缝参差,多于周身之帛缕;直栏横槛,多于九土之城郭;管弦呕哑,多于市人之言语。使天下之人,不敢言而敢怒。独夫之心,日益骄固。戍卒叫,函谷举,楚人一炬,可怜焦土!呜唿!灭六国者六国也,非秦也;族秦者秦也,非天下也。嗟乎!使六国各爱其人,则足以拒秦;使秦复爱六国之人,则递三世可至万世而为君,谁得而族灭也?秦人不暇自哀,而后人哀之;后人哀之而不鉴之,亦使后人而复哀后人也。少闻鸡声眠,老听鸡声起。千古万代人,消磨数声里。杪秋霜露重,晨起行幽谷。黄叶覆溪桥,荒村唯古木。寒花疏寂历,幽泉微断续。机心久已忘,何事惊麋鹿。悲时俗之迫阨兮,愿轻举而远游。质菲薄而无因兮,焉讬乘而上浮?遭沈浊而污秽兮,独郁结其谁语!夜耿耿而不寐兮,魂营营而至曙。惟天地之无穷兮,哀人生之长勤。往者余弗及兮,来者吾不闻。步徙倚而遥思兮,怊惝怳而乖怀。意荒忽而流荡兮,心愁悽而增悲。神倏忽而不反兮,形枯藁而独留。内惟省以操端兮,求正气之所由。漠虚静以恬愉兮,澹无为而自得。闻赤松之清尘兮,愿承风乎遗则。贵真人之休德兮,美往世之登仙;与化去而不见兮,名声着而日延。奇傅说之讬辰星兮,羡韩众之得一。形穆穆以浸远兮,离人群而遁逸。因气变而遂曾举兮,忽神奔而鬼怪。时仿佛以遥见兮,精晈晈以往来。超氛埃而淑邮兮,终不反其故都。免众患而不惧兮,世莫知其所如。恐天时之代序兮,耀灵晔而西征。微霜降而下沦兮,悼芳草之先蘦。聊仿佯而逍遥兮,永历年而无成。谁可与玩斯遗芳兮?长向风而舒情。高阳邈以远兮,余将焉所程?重曰:春秋忽其不淹兮,奚久留此故居。轩辕不可攀援兮,吾将从王乔而娱戏。餐六气而饮沆瀣兮,漱正阳而含朝霞。保神明之清澄兮,精气入而麤秽除。顺凯风以从游兮,至南巢而壹息。见王子而宿之兮,审壹气之和德。曰“道可受兮,不可传;其小无内兮,其大无垠。毋滑而魂兮,彼将自然;壹气孔神兮,于中夜存。虚以待之存,无为之先;庶类以成兮,此德之门。”闻至贵而遂徂兮,忽乎吾将行。仍羽人于丹丘,留不死之旧乡。朝濯发于汤谷兮,夕晞余身兮九阳。吸飞泉之微液兮,怀琬琰之华英。玉色頩以脕颜兮,精醇粹而始壮。质销铄以汋约兮,神要眇以淫放。嘉南州之炎德兮,丽桂树之冬荣;山萧条而无兽兮,野寂漠其无人。载营魄而登霞兮,掩浮云而上征。命天阍其开关兮,排阊阖而望予。召丰隆使先导兮,问太微之所居。集重阳入帝宫兮,造旬始而观清都。朝发轫于太仪兮,夕始临乎于微闾。屯余车之万乘兮,纷容与而并驰。驾八龙之婉婉兮,载云旗之逶蛇。建雄虹之采旄兮,五色杂而炫耀。服偃蹇以低昂兮,骖连蜷以骄骜。骑胶葛以杂乱兮,斑漫衍而方行。撰余辔而正策兮,吾将过乎句芒。历太皓以右转兮,前飞廉以启路。阳杲杲其未光兮,凌天地以径度。风伯为余先驱兮,氛埃辟而清凉。凤凰翼其承旂兮,遇蓐收乎西皇。揽慧星以为旍兮,举斗柄以为麾。叛陆离其上下兮,游惊雾之流波。时暧曃其曭莽兮,召玄武而奔属。后文昌使掌行兮,选署众神以并毂。路漫漫其修远兮,徐弭节而高厉。左雨师使径侍兮,右雷公以为卫。欲度世以忘归兮,意姿睢以抯挢。内欣欣而自美兮,聊媮娱以淫乐。涉青云以汎滥游兮,忽临睨夫旧乡。仆夫怀余心悲兮,边马顾而不行。思旧故以想象兮,长太息而掩涕。汜容与而遐举兮,聊抑志而自弭。指炎神而直驰兮,吾将往乎南疑。览方外之荒忽兮,沛罔瀁而自浮。祝融戒而跸御兮,腾告鸾鸟迎宓妃。张咸池奏承云兮,二女御九韶歌。使湘灵鼓瑟兮,令海若舞冯夷。玄螭虫象并出进兮,形蟉虬而逶蛇。雌蜺便娟以增挠兮,鸾鸟轩翥而翔飞。音乐博衍无终极兮,焉乃逝以徘徊。舒并节以驰骛兮,逴绝垠乎寒门。轶迅风于清源兮,从颛顼乎增冰。历玄冥以邪径兮,乘间维以反顾。召黔赢而见之兮,为余先乎平路。经营四方兮,周流六漠。上至列缺兮,降望大壑。下峥嵘而无地兮,上寥廓而无天。视倏忽而无见兮,听惝恍而无闻。超无为以至清兮,与泰初而为邻。来是空言去绝踪,月斜楼上五更钟。梦为远别啼难唤,书被催成墨未浓。蜡照半笼金翡翠,麝熏微度绣芙蓉。刘郎已恨蓬山远,更隔蓬山一万重。飒飒东风细雨来,芙蓉塘外有轻雷。金蟾啮锁烧香入,玉虎牵丝汲井回。贾氏窥帘韩掾少,宓妃留枕魏王才。春心莫共花争发,一寸相思一寸灰。含情春晼晚,暂见夜阑干。楼响将登怯,帘烘欲过难。多羞钗上燕,真愧镜中鸾。归去横塘晓,华星送宝鞍。何处哀筝随急管,樱花永巷垂杨岸。东家老女嫁不售,白日当天三月半。溧阳公主年十四,清明暖后同墙看。归来展转到五更,梁间燕子闻长叹。青青水中蒲,叶短不出水。妇人不下堂,行子在万里。

昼夜乐·冬拼音:

si yue qing he yu zha qing .nan shan dang hu zhuan fen ming .geng wu liu xu yin feng qi .wei you kui hua xiang ri qing .liu wang bi .si hai yi .shu shan wu .a fang chu .fu ya san bai yu li .ge li tian ri .li shan bei gou er xi zhe .zhi zou xian yang .er chuan rong rong .liu ru gong qiang .wu bu yi lou .shi bu yi ge .lang yao man hui .yan ya gao zhuo .ge bao di shi .gou xin dou jiao .pan pan yan .qun qun yan .feng fang shui wo .chu bu zhi qi ji qian wan luo .chang qiao wo bo .wei yun he long .fu dao xing kong .bu ji he hong .gao di ming mi .bu zhi xi dong .ge tai nuan xiang .chun guang rong rong .wu dian leng xiu .feng yu qi qi .yi ri zhi nei .yi gong zhi jian .er qi hou bu qi ..bu zhi hu yi zuo .bu zhi qi .xi dong yi zuo .dong xi .fei pin ying qiang .wang zi huang sun .ci lou xia dian .nian lai yu qin .chao ge ye xian .wei qin gong ren .ming xing ying ying .kai zhuang jing ye .lv yun rao rao .shu xiao huan ye .wei liu zhang ni .qi zhi shui ye .yan xie wu heng .fen jiao lan ye .lei ting zha jing .gong che guo ye .lu lu yuan ting .yao bu zhi qi suo zhi ye .yi ji yi rong .jin tai ji yan .man li yuan shi .er wang xing yan .you bu jian zhe .san shi liu nian ..you bu jian zhe yi zuo .you bu de jian zhe .yan zhao zhi shou cang .han wei zhi jing ying .qi chu zhi jing ying .ji shi ji nian .piao lue qi ren .yi die ru shan .yi dan bu neng you .shu lai qi jian .ding cheng yu shi .jin kuai zhu li .qi zhi li yi .qin ren shi zhi .yi bu shen xi .jie hu .yi ren zhi xin .qian wan ren zhi xin ye .qin ai fen she .ren yi nian qi jia .nai he qu zhi jin zi zhu .yong zhi ru ni sha .shi fu dong zhi zhu .duo yu nan mu zhi nong fu .jia liang zhi chuan .duo yu ji shang zhi gong nv .ding tou lin lin .duo yu zai yu zhi su li .wa feng can cha .duo yu zhou shen zhi bo lv .zhi lan heng jian .duo yu jiu tu zhi cheng guo .guan xian ou ya .duo yu shi ren zhi yan yu .shi tian xia zhi ren .bu gan yan er gan nu .du fu zhi xin .ri yi jiao gu .shu zu jiao .han gu ju .chu ren yi ju .ke lian jiao tu .wu hu .mie liu guo zhe liu guo ye .fei qin ye .zu qin zhe qin ye .fei tian xia ye .jie hu .shi liu guo ge ai qi ren .ze zu yi ju qin .shi qin fu ai liu guo zhi ren .ze di san shi ke zhi wan shi er wei jun .shui de er zu mie ye .qin ren bu xia zi ai .er hou ren ai zhi .hou ren ai zhi er bu jian zhi .yi shi hou ren er fu ai hou ren ye .shao wen ji sheng mian .lao ting ji sheng qi .qian gu wan dai ren .xiao mo shu sheng li .miao qiu shuang lu zhong .chen qi xing you gu .huang ye fu xi qiao .huang cun wei gu mu .han hua shu ji li .you quan wei duan xu .ji xin jiu yi wang .he shi jing mi lu .bei shi su zhi po e xi .yuan qing ju er yuan you .zhi fei bao er wu yin xi .yan tuo cheng er shang fu .zao shen zhuo er wu hui xi .du yu jie qi shui yu .ye geng geng er bu mei xi .hun ying ying er zhi shu .wei tian di zhi wu qiong xi .ai ren sheng zhi chang qin .wang zhe yu fu ji xi .lai zhe wu bu wen .bu xi yi er yao si xi .chao chang huang er guai huai .yi huang hu er liu dang xi .xin chou qi er zeng bei .shen shu hu er bu fan xi .xing ku gao er du liu .nei wei sheng yi cao duan xi .qiu zheng qi zhi suo you .mo xu jing yi tian yu xi .dan wu wei er zi de .wen chi song zhi qing chen xi .yuan cheng feng hu yi ze .gui zhen ren zhi xiu de xi .mei wang shi zhi deng xian .yu hua qu er bu jian xi .ming sheng zhuo er ri yan .qi fu shuo zhi tuo chen xing xi .xian han zhong zhi de yi .xing mu mu yi jin yuan xi .li ren qun er dun yi .yin qi bian er sui zeng ju xi .hu shen ben er gui guai .shi fang fo yi yao jian xi .jing jiao jiao yi wang lai .chao fen ai er shu you xi .zhong bu fan qi gu du .mian zhong huan er bu ju xi .shi mo zhi qi suo ru .kong tian shi zhi dai xu xi .yao ling ye er xi zheng .wei shuang jiang er xia lun xi .dao fang cao zhi xian ling .liao fang yang er xiao yao xi .yong li nian er wu cheng .shui ke yu wan si yi fang xi .chang xiang feng er shu qing .gao yang miao yi yuan xi .yu jiang yan suo cheng .zhong yue .chun qiu hu qi bu yan xi .xi jiu liu ci gu ju .xuan yuan bu ke pan yuan xi .wu jiang cong wang qiao er yu xi .can liu qi er yin hang xie xi .shu zheng yang er han chao xia .bao shen ming zhi qing cheng xi .jing qi ru er cu hui chu .shun kai feng yi cong you xi .zhi nan chao er yi xi .jian wang zi er su zhi xi .shen yi qi zhi he de .yue .dao ke shou xi .bu ke chuan .qi xiao wu nei xi .qi da wu yin .wu hua er hun xi .bi jiang zi ran .yi qi kong shen xi .yu zhong ye cun .xu yi dai zhi cun .wu wei zhi xian .shu lei yi cheng xi .ci de zhi men ..wen zhi gui er sui cu xi .hu hu wu jiang xing .reng yu ren yu dan qiu .liu bu si zhi jiu xiang .chao zhuo fa yu tang gu xi .xi xi yu shen xi jiu yang .xi fei quan zhi wei ye xi .huai wan yan zhi hua ying .yu se ping yi wen yan xi .jing chun cui er shi zhuang .zhi xiao shuo yi yue yue xi .shen yao miao yi yin fang .jia nan zhou zhi yan de xi .li gui shu zhi dong rong .shan xiao tiao er wu shou xi .ye ji mo qi wu ren .zai ying po er deng xia xi .yan fu yun er shang zheng .ming tian hun qi kai guan xi .pai chang he er wang yu .zhao feng long shi xian dao xi .wen tai wei zhi suo ju .ji zhong yang ru di gong xi .zao xun shi er guan qing du .chao fa ren yu tai yi xi .xi shi lin hu yu wei lv .tun yu che zhi wan cheng xi .fen rong yu er bing chi .jia ba long zhi wan wan xi .zai yun qi zhi wei she .jian xiong hong zhi cai mao xi .wu se za er xuan yao .fu yan jian yi di ang xi .can lian quan yi jiao ao .qi jiao ge yi za luan xi .ban man yan er fang xing .zhuan yu pei er zheng ce xi .wu jiang guo hu ju mang .li tai hao yi you zhuan xi .qian fei lian yi qi lu .yang gao gao qi wei guang xi .ling tian di yi jing du .feng bo wei yu xian qu xi .fen ai bi er qing liang .feng huang yi qi cheng qi xi .yu ru shou hu xi huang .lan hui xing yi wei jing xi .ju dou bing yi wei hui .pan lu li qi shang xia xi .you jing wu zhi liu bo .shi ai dai qi tang mang xi .zhao xuan wu er ben shu .hou wen chang shi zhang xing xi .xuan shu zhong shen yi bing gu .lu man man qi xiu yuan xi .xu mi jie er gao li .zuo yu shi shi jing shi xi .you lei gong yi wei wei .yu du shi yi wang gui xi .yi zi sui yi zha jiao .nei xin xin er zi mei xi .liao tou yu yi yin le .she qing yun yi fan lan you xi .hu lin ni fu jiu xiang .pu fu huai yu xin bei xi .bian ma gu er bu xing .si jiu gu yi xiang xiang xi .chang tai xi er yan ti .si rong yu er xia ju xi .liao yi zhi er zi mi .zhi yan shen er zhi chi xi .wu jiang wang hu nan yi .lan fang wai zhi huang hu xi .pei wang yang er zi fu .zhu rong jie er bi yu xi .teng gao luan niao ying mi fei .zhang xian chi zou cheng yun xi .er nv yu jiu shao ge .shi xiang ling gu se xi .ling hai ruo wu feng yi .xuan chi chong xiang bing chu jin xi .xing liu qiu er wei she .ci ni bian juan yi zeng nao xi .luan niao xuan zhu er xiang fei .yin le bo yan wu zhong ji xi .yan nai shi yi pai huai .shu bing jie yi chi wu xi .chuo jue yin hu han men .yi xun feng yu qing yuan xi .cong zhuan xu hu zeng bing .li xuan ming yi xie jing xi .cheng jian wei yi fan gu .zhao qian ying er jian zhi xi .wei yu xian hu ping lu .jing ying si fang xi .zhou liu liu mo .shang zhi lie que xi .jiang wang da he .xia zheng rong er wu di xi .shang liao kuo er wu tian .shi shu hu er wu jian xi .ting chang huang er wu wen .chao wu wei yi zhi qing xi .yu tai chu er wei lin .lai shi kong yan qu jue zong .yue xie lou shang wu geng zhong .meng wei yuan bie ti nan huan .shu bei cui cheng mo wei nong .la zhao ban long jin fei cui .she xun wei du xiu fu rong .liu lang yi hen peng shan yuan .geng ge peng shan yi wan zhong .sa sa dong feng xi yu lai .fu rong tang wai you qing lei .jin chan nie suo shao xiang ru .yu hu qian si ji jing hui .jia shi kui lian han yuan shao .mi fei liu zhen wei wang cai .chun xin mo gong hua zheng fa .yi cun xiang si yi cun hui .han qing chun wan wan .zan jian ye lan gan .lou xiang jiang deng qie .lian hong yu guo nan .duo xiu cha shang yan .zhen kui jing zhong luan .gui qu heng tang xiao .hua xing song bao an .he chu ai zheng sui ji guan .ying hua yong xiang chui yang an .dong jia lao nv jia bu shou .bai ri dang tian san yue ban .li yang gong zhu nian shi si .qing ming nuan hou tong qiang kan .gui lai zhan zhuan dao wu geng .liang jian yan zi wen chang tan .qing qing shui zhong pu .ye duan bu chu shui .fu ren bu xia tang .xing zi zai wan li .

昼夜乐·冬翻译及注释:

天宝以后,农村寂寞荒凉,家园里只剩下蒿草蒺藜。我的乡里百余户人家,因世道乱离都各奔东西。
(15)周子:周颙(yóng)。With hills and rills in sight, I miss the far-off in vain. How can I bear the fallen blooms in wind and rain! Why not enjoy the fleeting pleasure now again?
门:家门。高崖上飞腾直落的瀑布好(hao)像有几千尺,让人恍惚以为银河从天上泻落到人间。
檐(yán):屋顶伸出的部分。  失去了焉支山,我们放牧困难,生活贫困,妇女们因过着穷苦的日子都没有好的容颜。失去了祁连山,使我们丧失了良好的牧场,牲畜不能繁殖。我们是多么凄伤啊!
⒁此二句中有着杜甫自己的影子。古柏不知自炫,故曰不露文章。古柏本可作栋梁,故曰未辞剪伐。这就杜甫为人来说(shuo),即不怕牺(xi)牲,与“我能剖心血,饮啄慰孤愁”,“济时敢爱死,寂寞壮心惊”正是一副心肠。送,就木说,是移送:就人说,是保送或推荐。客舍前的梅花已经凋残,溪桥旁新生细柳轻垂,春风踏芳草远行人跃(yue)马(ma)扬鞭。走得越远离愁越没有穷尽,像那迢迢不断的春江之水(shui)。
藕花:荷花。

昼夜乐·冬赏析:

  一般读者都知道柳宗元的诗中总是充满了一种酸楚哀怨,凄婉幽深和感厄愤郁之情。特别是在永州所作诗篇,取境大都以清冷、幽僻、寂静为主色调,读起来给人以郁闷压抑、吞吞吐吐的感觉,总缺少一些豪迈潇洒、明快超脱。而此诗却一反常态,使人耳目一新,在柳宗元诗集中,可算得上十分难得的“快诗”。
  第一首题咏诗的着眼处在于水面及其近岸的林木,从而呈现出一片清疏旷远之景。
  全诗三章,皆为四句。每句两个音拍。前两章运用回环复沓的艺术手法,渲染环境气氛,突出事物特点。且以工整的排列。朗朗上口的语言形式,尽情抒发抑郁情感,增强了音乐效果。第三章则转变风格,避免通篇一致的枯燥感,显得起伏有致,使得诗作的另一突出特点是通篇明白晓畅,语言通俗易懂,未明颠倒狂夫不能等都是人们常用的日常语言,以此为诗质朴自然,充满无限的生命。[4] 《齐风·《东方未明》佚名 古诗》在结构形式和艺术手法上也很有特点。其一,《《东方未明》佚名 古诗》为乐歌,在结构上回环复沓。第一章和第二章中有些句子只换了一个或几个字。 这种回复重叠,规律中有变化,严格中有自由,既是歌唱时的和声,也是表述意思的层层递进和对内涵的强化作用。(《随园诗话》)但就作诗而言,重词叠句与反复咏唱是为着尽情抒发情感的需要,这在《诗经》其他诗作中和后世民歌中也经常运用。这样有利于突出事物特征,渲染环境气氛,增强音乐效果,给人留下深刻难忘的印象;同时,也便于记忆与传诵。其二,诗人善于通过细节的描绘来反映生活。例如“颠倒衣裳”的细节描写, 其三,语言通俗易懂,读之琅琅上口。例如“东方”、“未明”、“颠倒”、“倒颠”、“狂夫”、“不能”等词汇,都是人们常用的口头语言,用在诗中,质朴自然,恰如其分。这些词语历经了三千余年的风雨,仍然葆有无限的生命力,至今保存在人们的口头与书面用语之中。此外,全诗以四言句为形式,每句两个音拍,二二的节奏。前两章排列工整,键行和押韵有规律;第三章则起伏有致,跌宕变化。这种不拘一格的韵律节奏,也体现了当时劳动人民口头歌谣创作的艺术特点。
  诗歌语言朴直清新,明白如话,表现出一种“由工入微,不犯痕迹”的精湛功夫。
  第四句以“桐枯凤死”暗喻李商隐的去世。《庄子·秋水》:“夫鹓雏发于南海而飞于北海,非梧桐不止,非练实(竹实)不食,非醴泉不饮”,足见其高贵。这鹓雏即是凤一类的鸟。李商隐在科第失意时,曾把排抑他的人比作嗜食腐鼠的鸱鸟,而自喻为鹓雏(《安定城楼》:“不知腐鼠成滋味,猜意鹓雏竟未休”)。当时凤在,就无桐可栖,无竹可食。此时竹死,桐枯,凤亡,就更令人悲怆了。此句用字平易、精审,可谓一哭三叹也。
  此诗读来如听诗人倾诉自己身受的离乱之苦。在这战乱饥馑灾难深重的年代里,祖传的家业荡然一空,兄弟姊妹抛家失业,羁旅行役,天各一方。回首兵燹后的故乡田园,一片寥落凄清。破敝的园舍虽在,可是流离失散的同胞骨肉,却各自奔波在异乡的道路之中。诗的前两联就是从“时难年荒”这一时代的灾难起笔,以亲身经历概括出战乱频年、家园荒残、手足离散这一具有典型意义的苦难的现实生活。接着诗人再以“雁”、“蓬”作比:手足离散各在一方,犹如那分飞千里的孤雁,只能吊影自怜;辞别故乡流离四方,又多么像深秋中断根的蓬草,随着萧瑟的西风,飞空而去,飘转无定。“吊影分为千里雁,辞根散作九秋蓬”两句,一向为人们所传诵。诗人不仅以千里孤雁、九秋断蓬作了形象贴切的比拟,而且以吊影分飞与辞根离散这样传神的描述,赋予它们孤苦凄惶的情态,深刻揭示了饱经战乱的零落之苦。孤单的诗人凄惶中夜深难寐,举首遥望孤悬夜空的明月,情不自禁联想到飘散在各地的兄长弟妹们。他想:如果此时大家都在举目遥望这轮勾引无限乡思的明月,也会和自己一样潸潸泪垂吧!恐怕这一夜之中,流散五处深切思念家园的心,也都会是相同的。诗人在这里以绵邈真挚的诗思,构出一幅五地望月共生乡愁的图景,从而收结全诗,创造出浑朴真淳、引人共鸣的艺术境界。
  其二

俞绣孙其他诗词:

每日一字一词