(1):

(a.) Dependent on choice; bestowed or passing by election; as, an elective study; an elective office.

(2):

(a.) Pertaining to, or consisting in, choice, or right of choosing; electoral.

(3):

(n.) In an American college, an optional study or course of study.

(4):

(a.) Exerting the power of choice; selecting; as, an elective act.