What is the meaning of Trimester?

A period of three months or about three months; : quarter.

One of the terms of an academic year in those learning institutions that divide their teaching in three roughly equal terms, each about three months long. Compare semester.

trimester

trimester (period of three months)

trimester: a period of three months or about three months

divisions of pregnancy period, each lasting for approximately 3 months

trimester

Source: wiktionary.org