elective (electives plural )
1 adj An elective post or committee is one to which people are appointed as a result of winning an election.
FORMAL Buchanan has never held elective office.
2 adj Elective surgery is surgery that you choose to have before it becomes essential.
FORMAL
3 n-count An elective is a subject which a student can choose to study as part of his or her course.
(AM)
in BRIT, use option