| 三 | sān | three; 3 |
| 三角形 | sān jiǎo xíng | triangle |
| 直角三角形 | zhí jiǎo sān jiǎo xíng | a right angled triangle |
| 三极管 | sān jí guǎn | triode (vacuum tube or transistor) |
| 三角函数 | sān jiǎo hán shù | trigonometric function |
| 三国 | Sān guó | Three Kingdoms period (220-280) in Chinese history; several Three Kingdoms periods in Korean history, esp. from 1st century AD to unification under Silla 新罗 in 658 |
| 第三世界 | dì sān shì jiè | Third World |
| 三角 | sān jiǎo | triangle |
| 三峡 | Sān xiá | Sanhsia town in Taipei county 台北县, Taiwan; Three Gorges on the Changjiang or Yangtze, namely: Qutang Gorge 瞿塘峡, Wuxia Gorge 巫峡 and Xiling Gorge 西陵峡 |
| 三世 | sān shì | the Third (of named Kings) |
| 三国志 | Sān guó zhì | History of the Three Kingdoms, fourth of the 24 dynastic histories 二十四史, composed by Chen Shou 陈寿 in 289 during Jin Dynasty 晋朝, 65 scrolls |
| 三代 | sān dài | third-generation |
| 再三 | zài sān | over and over again; again and again |
| 三角板 | sān jiǎo bǎn | set square; triangle (for drawing right angles) |
| 等边三角形 | děng biān sān jiǎo xíng | equilateral triangle |
| 三军 | sān jūn | (in former times) upper, middle and lower army; army of right, center and left; (in modern times) the three armed services: Army, Navy and Air Force |
| 三民主义 | sān mín zhǔ yì | Dr Sun Yat-sen's 孙中山 Three principles of the people (late 1890s) |
| 三和弦 | sān hé xián | triad; musical chord of three notes, such as major triad do-mi-so |
| 十三点 | shí sān diǎn | half-witted; nitwit |
| 三台 | Sān tái | Santai county in Mianyang 绵阳, north Sichuan |
| 三纲五常 | sān gāng wǔ cháng | three principles and five virtues (idiom); the three rules (ruler guides subject, father guides son and husband guides wife) and five constant virtues of Confucianism (benevolence 仁, righteousness 义, propriety 礼, wisdom 智 and fidelity 信) |
| 三权分立 | sān quán fēn lì | separation of powers |
| 三棱镜 | sān léng jìng | (triangular) prism |
| 三门 | Sān mén | Sanmen county in Taizhou 台州, Zhejiang |
| 三国演义 | Sān guó Yǎn yì | Romance of the Three Kingdoms by Luo Guanzhong 罗贯中, one of the Four Classic Novels of Chinese literature; a fictional account of the Three Kingdoms at the break-up of the Han around 200 AD, consistently portraying Liu Bei's Shu Han 劉備, 刘备, 蜀汉 as virtuous heroes and Cao Cao's Wei 曹操, 魏 as tyrannical villains |
| 三原 | Sān yuán | Sanyuan county in Xiányáng 咸阳, Shǎnxī 陕西 |
| 三宝 | sān bǎo | the Three Precious Treasures of Buddhism, namely: the Buddha 佛, the Dharma 法 (his teaching), and the Sangha 僧 (his monastic order) |
| 三项式 | sān xiàng shì | trinomial (math.) |
| 三脚架 | sān jiǎo jià | tripod; derrick crane |
| 三更 | sān gēng | third of the five night watch periods 23:00-01:00 (old); midnight |
| 第三者 | dì sān zhě | sb who is romantically involved with sb already in a committed relationship; the other woman; the other man; abbr. to 小三; third person; third party (in dispute); disinterested party; number three in a list |
| 三部曲 | sān bù qǔ | trilogy |
| 三侠五义 | Sān xiá wǔ yì | Sanxia wuyi (lit. Three knight-errants and five righteous one), novel edited from stories of late Qing dynasty pinghua 评话 master storyteller Shi Yukun 石玉昆 |
| 三水 | Sān shuǐ | Sanshui district of Foshan city 佛山市, Guangdong |
| 三角洲 | sān jiǎo zhōu | delta (geography) |
| 三轮车 | sān lún chē | pedicab; tricycle |
| 第三纪 | dì sān jì | third period; tertiary (geological era since the extinction of the dinosaurs at the Cretaceous-Tertiary boundary 65 million years ago) |
| 接二连三 | jiē èr lián sān | one after another (idiom); in quick succession |
| 约法三章 | yuē fǎ sān zhāng | to agree on three laws (idiom); provisional agreement made by new dynastic government with the people |
| 三废 | sān fèi | three types of waste product, namely: waste water 废水, exhaust gas 废气, industrial slag 废渣 |
| 三个世界 | sān gè shì jiè | three worlds, i.e. Western capitalism, Soviet communism and the non-aligned countries |
| 三门峡 | Sān mén xiá | Sanmenxia prefecture level city in Henan |
| 三星 | sān xīng | three major stars of the Three Stars 参宿 Chinese constellation; the belt of Orion; three spirits 福, 禄, and 寿 associated with the Three Stars 参宿 Chinese constellation; Sanxing or Sanhsing township in Yilan county 宜兰县, Taiwan; Samsung (South Korean electronics company) |
| 三角学 | sān jiǎo xué | trigonometry |
| 三通 | sān tōng | T-joint; T-piece; T-pipe; three links |
| 珠江三角洲 | Zhū jiāng sān jiǎo zhōu | Pearl River Delta (PRD) |
| 三三两两 | sān sān liǎng liǎng | in twos and threes |
| 三弦 | sān xián | sanxian, large family of 3-stringed plucked musical instruments, with snakeskin covered wooden soundbox and long neck, used in folk music, opera and Chinese orchestra |
| 三从四德 | sān cóng sì dé | Confucian moral injunctions for women, namely: obey in turn three men father, husband and son, plus the four virtues of morality 德, physical charm 容, propriety in speech 言 and efficiency in needlework 功 |
| 三叉戟 | sān chā jǐ | trident |
