- 二等公民 èrděnggōngmín second-class citizenA discriminatory term used in some societies for people of low status or those who are impoverished
- 二等兵 èrděngbīng private second classa soldier of low rank, such as a private second class or an aircraftman
- 二等分 èrděngfēn to bisect; bisectionto divide, or the act of dividing, something into two equal parts (as a line, surface, or solid)
- 二等分线 èrděngfēnxiàn bisectora straight line that divides a geometric figure, such as an angle or a line segment, into two equal parts
- 二等舱 èrděngcāng second-class cabinsecond-class cabin, such as on a ship or boat or train
- 二等车 èrděngchē second-class carriagesecond-class carriage of a train
- 二等边三角形 èrděngbiānsānjiǎoxíng isosceles trianglea triangle with at least two sides of equal length
