trimester

1. N-COUNT The first trimester of a pregnancy is the first three months of the pregnancy. The second trimester is the period from three months to six months, and the third trimester is the period from six months to nine months. (懷孕期的)三個月

At the end of the first trimester, the fetus is about three inches long. 在懷孕的第三個月末，胎兒差不多有三英寸長了。

2. N-COUNT In colleges and universities in some countries, a trimester is one of the three main periods into which the year is divided. (一些國家的學院及大學中一學年的三分之一)學期

...the proposed school's trimester calendar. ...這份擬定的學校學期日歷。