1. trimester(n = noun.time) Array - a period of three months; especially one of the three three-month periods into which human pregnancy is divided; Array
is a kind of period, period of time, time period
is a part of gestation, gestation period
has particulars: first trimester, second trimester, third trimester
2. trimester(n = noun.time) Array - one of three divisions of an academic year; Array
is a kind of academic session, academic term, school term, session
is a part of academic year, school year
A term or period of three months. [1913 Webster]
trimester, n. a period of three months, esp. of human gestation or US as a university term.
Derivative:
trimestral adj. trimestrial adj.
Etymology:
F trimestre f. L trimestris (as TRI-, - mestris f. mensis month)