| 一号 | yī hào | first day of the month |
| 一号木杆 | yī hào mù gān | driver (golf) |
| 一号电池 | yī hào diàn chí | D size battery |
| 一见倾心 | yī jiàn qīng xīn | love at first sight |
| 一见如故 | yī jiàn rú gù | familiarity at first sight |
| 一见钟情 | yī jiàn zhōng qíng | love at first sight (idiom) |
| 一见高低 | yī jiàn gāo dī | lit. to fight it out with sb to see who is best (idiom); fig. to cross swords with; to lock horns |
| 一览无遗 | yī lǎn wú yí | be plainly visible |
| 一角银币 | yī jiǎo yín bì | dime |
| 一触即溃 | yī chù jí kuì | to collapse on the first encounter; to give way at once |
| 一触即发 | yī chù jí fā | could happen at any moment; on the verge |
| 一言 | yī yán | one sentence; brief remark |
| 一言一行 | yī yán yī xíng | words and deeds (idiom) |
| 一言不发 | yī yán bù fā | to not say a word (idiom) |
| 一言九鼎 | yī yán jiǔ dǐng | one word worth nine sacred tripods (idiom); words of enormous weight |
| 一言以蔽之 | yī yán yǐ bì zhī | one word says it all (idiom, from Analects); to cut a long story short; in a nutshell |
| 一言千金 | yī yán qiān jīn | one word worth a thousand in gold (idiom); valuable advice; words of enormous weight |
| 一言抄百总 | yī yán chāo bǎi zǒng | to cut a long story short |
一言既出，
驷马难追 | yī yán jì chū ,
sì mǎ nán zhuī | lit. once said, a team of horses cannot unsay it (idiom); a promise must be kept |
| 一言为定 | yī yán wéi dìng | one word and it's settled (idiom); It's a deal!; That's settled then. |
| 一言为重 | yī yán wéi zhòng | each word carries weight; a promise must be kept (idiom) |
| 一言难尽 | yī yán nán jìn | hard to explain in a few words (idiom); complicated and not easy to express succinctly |
| 一语不发 | yī yǔ bù fā | to not say a word (idiom) |
| 一语双关 | yī yǔ shuāng guān | to make a pun; to have a double meaning; double entendre |
| 一诺千金 | yī nuò qiān jīn | a promise worth one thousand in gold (idiom); a promise that must be kept |
| 一走了之 | yī zǒu liǎo zhī | to avoid a problem by walking away from it; to quit |
| 一路来 | yī lù lái | all the way; all along; since the start |
| 一路发 | yī lù fā | fortune street (idiom) |
| 一蹴即至 | yī cù jí zhì | to get there in one step (idiom); easily done; success at a stroke; to get results overnight |
| 一蹴可几 | yī cù kě jǐ | succeed at the first try (idiom); easy as pie; one can do it at once |
| 一蹴而就 | yī cù ér jiù | to get there in one step (idiom); easily done; success at a stroke; to get results overnight |
| 一蹴而得 | yī cù ér dé | to get there in one step (idiom); easily done; success at a stroke; to get results overnight |
| 一跃而起 | yī yuè ér qǐ | to jump up suddenly; to bound up; to rise up in one bound |
| 一身汗 | yī shēn hàn | sweating all over |
| 一较高下 | yī jiào gāo xià | to compete against; to measure oneself against; to go head to head (see who is best) |
| 一轮 | yī lún | first round or stage (of a match, election, talks, planned policy etc) |
| 一转眼 | yī zhuǎn yǎn | in a wink |
| 一辞莫赞 | yī cí mò zàn | to be unable to offer an opinion (idiom) |
| 一退六二五 | yī tuì liù èr wǔ | lit. 1 divided by 16 is 0.0625 (abacus rule); fig. to deny responsibility; to pass the buck; also written 一推六二五 |
| 一通 | yī tòng | one time; once |
| 一连串 | yī lián chuàn | a chain of (events, errors, jobs, problems, successes etc); a succession of (disasters); a series; a row (of stores) |
| 一遍 | yī biàn | one time (all the way through); once through |
| 一遍又一遍 | yī biàn yòu yī biàn | over and over |
| 一针见血 | yī zhēn jiàn xiě | lit. to draw blood on the first prick; fig. to hit the nail on the head |
| 一钱不值 | yī qián bù zhí | not worth a penny; utterly worthless |
| 一错再错 | yī cuò zài cuò | to repeat errors; to continue blundering; to make continuous mistakes |
| 一门心思 | yī mén xīn si | to set one’s heart on sth (idiom) |
| 一闪念 | yī shǎn niàn | sudden idea; flash of insight |
| 一阵子 | yī zhèn zi | short period of time; while (time); fit of anger |
| 一霎 | yī shà | in a flash |
