n.
Pronunciation: s ə - ' mes-t ə r
Function: noun
Etymology: German, from Latin semestris half-yearly, from sex six + mensis month ― more at SIX , MOON
Date: 1827
1 : either of the two usually 18-week periods of instruction into which an academic year is often divided
2 : a period of six months
– se · mes · tral \ -tr ə l \ or se · mes · tri · al \ -tr ē - ə l \ adjective