- trimester (n.)
[trimester 词源字典]
- 1821, "period of three months," from French trimestre (early 17c.), from Latin trimestris "of three months," from tri- "three" (see tri-) + mensis "month" (see moon (n.)). Specific obstetrics sense is attested from 1916. Related: Trimestrial.[trimester etymology, trimester origin, 英语词源]