A midterm school exam (i.e., halfway through the term). / A midterm election.

Halfway through a term, or roughly so.

plural of midterm

(US) An election held every four years to elect members of Congress in years the president is not also elected.

plural of midterm election

A break (frequently, week-long) in classes taking place somewhere between the end of the first third and start of the last third of a semester (term), this may coincide with a mid-semester examination period (midterms).

In the middle of a terminal region