IPA: //bɪˈmɛstər//
KK: /ˈbɪmɛstər/
A time period that lasts for two months.
The school year is divided into four bimesters.
Bimester → It is formed from "bi-" (meaning two) and "mester" (from Latin "menses", meaning months). The word refers to a period of two months.
Think of 'bi-' meaning two, and 'mester' relating to months — so a bimester is a two-month period.