American English

Definition of trimester noun from the Oxford Advanced American Dictionary



    , NAmE//ˈtraɪmɛstər//
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  1. 1(medical) a period of three months during the time when a woman is pregnant the first trimester of pregnancy
  2. 2one of the three periods in the year during which classes are held in schools, universities, etc. The school year is divided into three trimesters. compare semester
See the Oxford Advanced Learner's Dictionary entry: trimester