noun, adverb
last semester
Refers to the previous academic term. Can be used as a noun or adverbially.
先学期は数学の成績が良かった。
Last semester my math grades were good.
先学期、彼は一度も休まなかった。
Last semester he never missed a class.
Means 'next semester', forming a natural set with 先学期 and 今学期.
Compound of 先 (previous) and 学期 (semester). The reading せんがっき follows regular rendaku voicing of がく to がっ.