| 三体问题 | sān tǐ wèn tí | three-body problem (mechanics) |
| 三魂 | sān hún | three immortal souls in Daoism, representing spirit and intellect; contrasted with 三魂 七魄 seven mortal forms |
| 三魂七魄 | sān hún qī pò | three immortal souls and seven mortal forms in Daoism, contrasting the spiritual and carnal side of man |
| 三鲜 | sān xiān | three fresh ingredients (in cooking) |
| 三鹿 | sān lù | Three Deer (brand) |
| 三鹿集团 | Sān lù jí tuán | Sanlu or Three deer, major PRC dairy company involved in 2008 melamine poisoning scandal |
| 三点水 | sān diǎn shuǐ | name of "water" radical in Chinese characters (Kangxi radical 85); see also 氵 |
| 不三不四 | bù sān bù sì | dubious; shady; neither one thing nor the other; neither fish nor fowl; nondescript |
不孝有三，
无后为大 | bù xiào yǒu sān ,
wú hòu wéi dà | There are three ways to be unfilial; having no sons is the worst. (citation from Mencius 孟子 ) |
| 不等边三角形 | bù děng biān sān jiǎo xíng | scalene triangle |
| 不管三七二十一 | bù guǎn sān qī èr shí yī | regardless of the consequences; recklessly relying on a hopelessly optimistic forecast |
| 不规则三角形 | bù guī zé sān jiǎo xíng | scalene triangle (math.) |
| 丙三醇 | bǐng sān chún | glycerine; same as 甘油 |
| 九三学社 | jiǔ sān xué shè | Jiusan Society |
| 乾嘉三大家 | Qián Jiā sān dà jiā | Three great poets of the Qianlong and Jiaqing era (1735-1820), namely: Yuan Mei 袁枚, Jiang Shiquan 蒋士铨 and Zhao Yi 赵翼 |
| 二氯异三聚氰酸钠 | èr lǜ yì sān jù qíng suān nà | sodium dichloroisocyanurate |
| 伊洛瓦底三角洲 | Yī luò wǎ dǐ sān jiǎo zhōu | Irrawaddy delta in south Myanmar (Burma) |
| 低三下四 | dī sān xià sì | servile |
| 传三过四 | chuán sān guò sì | to spread rumors; to gossip |
| 入木三分 | rù mù sān fēn | written in a forceful hand; penetrating; profound |
| 两岸三地 | liǎng àn sān dì | China, Taiwan, Hong Kong and Macau (media term used esp. since 1997) |
| 两面三刀 | liǎng miàn sān dāo | two-faced, three knives (idiom); double-cross; double dealing and back stabbing |
| 八二三炮战 | bā èr sān pào zhàn | bombardment of Kinmen by PRC forces that started August 23rd 1958, also called second Taiwan strait crisis |
| 六韬三略 | liù tāo sān lüè | "Six Secret Strategic Teachings” 六韬 and ”Three Strategies of Huang Shigong” 三略[San1 Lu:e4], two of the Seven Military Classics of ancient China 武经七书 |
| 其三 | qí sān | thirdly; the third |
| 再三再四 | zài sān zài sì | repeatedly; over and over again |
| 再衰三竭 | zài shuāi sān jié | weakening and close to exhaustion (idiom); in terminal decline; on one's last legs |
冰冻三尺，
非一日之寒 | bīng dòng sān chǐ ,
fēi yī rì zhī hán | three feet of ice does not form in a single day (idiom); Rome wasn't built in a day |
| 十三 | shí sān | thirteen; 13 |
| 十三日 | shí sān rì | thirteenth day of a month |
| 十三经 | shí sān jīng | the Thirteen Confucian Classics, namely: Book of Songs 诗经, Book of History 尚书, Rites of Zhou 周礼, Rites and Ceremonies 仪礼, Classic of Rites 礼记, Book of Changes 周易, Mr Zuo's Annals 左传, Mr Gongyang's Annals 公羊传, Mr Gu Liang's Annals 谷梁传, The Analects 论语, Erya 尔雅, Classic of Filial Piety 孝经, Mencius 孟子 |
| 半夜三更 | bàn yè sān gēng | in the depth of night; late at night |
| 南三角座 | nán sān jiǎo zuò | Triangulum Australe (constellation) |
| 周三径一 | zhōu sān jìng yī | circumference of a circle is proverbially three times its radius |
| 唐三藏 | Táng sān zàng | Tripitaka (602-664) Tang dynasty Buddhist monk and translator, who traveled to India 629-645; same as 玄奘 |
| 唐诗三百首 | Táng shī sān bǎi shǒu | Three hundred Tang dynasty poems, a stable anthology collected around 1763 by Sun Zhu 孫誅 |
| 四分之三 | sì fēn zhī sān | three quarters |
| 地三鲜 | dì sān xiān | dish consisting of stir-fried potato, eggplant and green pepper |
| 垂涎三尺 | chuí xián sān chǐ | to drool (over) (idiom); to yearn for; to covet; to crave |
| 增三和弦 | zēng sān hé xián | augmented triad (musical chord) |
| 大三 | dà sān | third-year university student |
| 大三和弦 | dà sān hé xián | major triad do-mi-so |
| 大三度 | dà sān dù | major third (musical interval) |
| 大小三度 | dà xiǎo sān dù | major and minor third (musical interval) |
| 大江健三郎 | Dà jiāng Jiàn sān láng | Oe Kenzaburo (1935-) Japanese novelist and 1994 Nobel laureate |
| 太子十三峰 | Tài zǐ shí sān fēng | thirteen peaks of Meri snow mountains in Diqing Tibetan autonomous prefecture 迪庆藏族自治州, Yunnan; also written 梅里雪山 |
| 安倍・晋三 | Ān bèi · Jìn sān | ABE Shinzō (1954-), Japanese LDP politician, prime minister 2006-2007 |
| 小三 | xiǎo sān | sb who is romantically involved with sb already in a committed relationship; the other woman; the other man; abbr. for 第三者 |
| 小三和弦 | xiǎo sān hé xián | minor triad la-do-mi |
| 小三度 | xiǎo sān dù | minor third (musical interval) |
