| 同情者 | tóng qíng zhě | supporter; sympathizer (esp. of political cause); fellow traveler |
| 同态 | tóng tài | homomorphism (math.) |
| 同房 | tóng fáng | to cohabit (esp. to live as man and wife) |
| 同文馆 | Tóng wén guǎn | the first modern Chinese library established in 1898 by William A.P. Martin 丁韪良, becoming the foundation for Beijing University library |
| 同日 | tóng rì | same day; simultaneous |
| 同日而语 | tóng rì ér yǔ | lit. to speak of two things on the same day (idiom); to mention things on equal terms (often with negatives: you can't mention X at the same time as Y) |
| 同时代 | tóng shí dài | contemporary |
| 同时期 | tóng shí qī | at the same time; contemporary |
| 同案犯 | tóng àn fàn | accomplice |
| 同桌 | tóng zhuō | desk-mate; seat-mate |
| 同业 | tóng yè | same trade or business; person in the same trade or business |
| 同业拆借 | tóng yè chāi jiè | call loan; short term loan within banking |
| 同构 | tóng gòu | isomorphism; isomorphic |
| 同步加速器 | tóng bù jiā sù qì | synchrotron |
| 同步数位阶层 | tóng bù shù wèi jiē céng | synchronous digital hierarchy; SDH |
| 同江 | Tóng jiāng | Tongjiang county level city in Kiamusze or Jiamusi city 佳木斯, Heilongjiang |
| 同江市 | Tóng jiāng shì | Tongjiang county level city in Kiamusze or Jiamusi city 佳木斯, Heilongjiang |
| 同流合污 | tóng liú hé wū | to wallow in the mire with sb (idiom); to follow the bad example of others |
| 同源词 | tóng yuán cí | cognate; words having a common origin |
| 同济 | Tóng jì | abbr. of 同济大学 |
| 同济大学 | Tóng jì Dà xué | Tongji University |
| 同济医科大学 | Tóng jì Yī kē Dà xué | Tongji Medical College |
| 同班 | tóng bān | to be in the same class; to be in the same squad; classmate |
| 同班同学 | tóng bān tóng xué | classmate |
| 同理 | tóng lǐ | for the same reason; Tongli, a city in Jiangsu Province, China |
| 同理心 | tóng lǐ xīn | empathy |
| 同甘苦 | tóng gān kǔ | to share joys and sorrows; sharing good times and hard times; same as 同甘共苦 |
| 同病相怜 | tóng bìng xiāng lián | fellow sufferers empathize with each other (idiom); misery loves company |
| 同砚 | tóng yàn | classmate; fellow student |
| 同窗 | tóng chuāng | schoolmate; fellow student |
| 同符合契 | tóng fú hé qì | same sign, joint aim (idiom); fig. completely compatible; identical |
| 同级 | tóng jí | on the same level; ranking equally |
| 同级评审 | tóng jí píng shěn | peer review |
| 同义 | tóng yì | synonym |
| 同义反复 | tóng yì fǎn fù | tautology |
| 同义字 | tóng yì zì | synonym |
| 同义词 | tóng yì cí | synonym |
| 同义语 | tóng yì yǔ | synonym |
| 同翅目 | tóng chì mù | Homoptera (insect suborder including cicadas, aphids, plant-hoppers, shield bugs etc) |
| 同声一哭 | tóng shēng yī kū | to share one’s feeling of grief with others (idiom) |
| 同声传译 | tóng shēng chuán yì | simultaneous interpretation |
| 同声翻译 | tóng shēng fān yì | simultaneous translation |
| 同胞兄妹 | tóng bāo xiōng mèi | sibling |
| 同舟共济 | tóng zhōu gòng jì | cross a river in the same boat (idiom); fig. having common interests; obliged to collaborate towards common goals |
| 同调 | tóng diào | same tone; in agreement with; homology (invariant of a topological space in math.) |
| 同质 | tóng zhì | homogeneous |
| 同路 | tóng lù | to go the same way |
| 同轴 | tóng zhóu | coaxial; concentric |
| 同轴圆弧 | tóng zhóu yuán hú | coaxial circular arc; concentric arc (in spherical geometry) |
| 同途殊归 | tóng tú shū guī | same road out, different ones back |
