一朝一夕

一朝一夕 一朝 一早 一夕 一晚 形容一天是很短的時間。
一朝一夕 means a short period of time, just a day. 一朝 is one morning. 一夕 is one night. Combining is a day.

一視同仁

一視同仁是對每個人一樣的好。
一視同仁 means treat everybody the same, no bias and prejudice.一視 one sight, one look. 同 same. 仁 person, interacting the same.

一勞永逸

一勞永逸，辛苦一次換來永遠安逸，安樂。
一勞永逸 is to say to get the long term peaceful life, just need to work very hard for once. 一勞 one hard work, to exchange 永逸 forever peaceful and enjoyable life. 永 is forever. 逸 is opposite of working very hard.

一貧如洗

一貧如洗是很窮，甚麽也沒有，像洗過的乾淨。
一貧如洗 describe how poor it is, so poor that just newly cleaned, nothing left. 一貧 is one poor, one is so poor, that 如洗 like washed, cleaned. One has nothing left, that poor.

一揮而就

一揮而就是一動起筆就完成了。
一揮而就 is to describe how fast it is to finish 而就, just one stroke, or one whip 一揮。 就 is finished, done, achieved.

一望而知

一望而知是一看便知，明白。
一望而知 means easy to understand with one quick look. 一望 one look 而知 then know.

一掃而光

一掃而光意思是很快便掃到沒有了。掃另有意思是購買。
一掃而光 means wiping quickly, implied "dust" is gone very quickly. 一掃 one wipe. 而光 become nothing, vanished. 光 can means bright or light but here means empty to shiny (in empty box). The other meaning of 掃 is buy. In this token, meaning everthing is bought, sold, cleared or cleaned up.

一乾二淨

一乾二淨就等於乾淨，一無所有。
一乾二淨 means clean but is expressed as emptiness, nothing is left. 一乾 one dry 二淨 two clean or second none. Expressing nothing more than that clean.

一敗塗地

一敗塗地表示完全地失敗。
一敗塗地 means failure to the extreme, cocmpletely failed. 一敗 one failure or one lose. 塗地 painting, brushing the floor. Bad failure.

一馬當先

一馬當先意思是走在前面，做別人的榜樣，不退縮。
一馬當先 means being the first one to go forward, setting an examle and not retrieving. 一馬 one horse 當先 being the first, leader or pioneer.

一針見血

一針見血比喻說話精簡直接地入題〔要害〕。
一針見血 implies some words is right to the point or points right to the problem. 一針 is one needle. 見血 see the blood. Combining the action, getting the blood with just one shot using the needle is to express the truth fact, right to the point.

一笑置之

一笑置之表示不當是一回事，不會計較。
一笑置之 express the attitude of not taking what's been done seriously or not to worry or bargain about anything. 一笑 is one smile. 置之 is put it somewhere or on one side, interpret that as leting it go. 之 is the thing, what's been done bad.

一脈相承

一脈相承比喻相傳承接的關係。
一脈相承 means the sole inheritance. 一脈 is one vein or branch, 相承 mutually connected and inherited. 承 can be meant supported.

一氣呵成

一氣呵成是一口氣地完成，有形容文章緊凑連貫着。
一氣呵成 is to say finish some task without any break. In essay, the story is tightly linked. 一氣 one breath, 氣 also mean air, here means breathing (air). 呵成 means to completion. 呵 is just the sound to describe going.

一息尚存

一息尚存是逞活着，息是氣息、呼吸，存是在、有。
一息尚存 means still alive. 一息 is one breath. 尚存 is still exist.

一差二錯

一差二錯是疏漏或差錯。
一差二錯 is describe a couple mistakes, overlooking or doing something wrong. 一差 is one difference, 二錯 is two mistakes.

一哄而散

一哄而散說的是一嚷就散了，只須喊一聲，所有人都走了。
一哄而散 describe how fast the group is disintegrated. Just a shout, everybody is gone. 一哄 one scream or shout, 而 then 散 fly away, broken into pieces, meaning all gone.

一面之詞

一面之詞是單方面說的並不全面，不足信。
一面之詞 is what is said is only from one person's point of view. 一面 is one side, 之 is 'of' and 詞 is the word. The word is only from one side or only one's story, not really credible.

一事無成

一事無成是什麽事(工作)也做不了，沒有任何成就。
一事無成 is saying someone cannot do anything, no accomplishment. 一事 is one thing, 無成 is no achievement.

一板三眼

一板三眼比喻有規有矩，做事有紋有路，有多少死板，不懂轉彎〔不靈活〕。板眼是中樂節拍。
一板三眼describe a person performing a task with good steps, skills. He knows how to do thing in proper way. Negative notion is not flexible enough. 一 is one, 板眼 is musical bits, notes, 三 is three. 板 is sheet of wood and 眼 is eye for direct meaning.