elective
adjectiveUK /ɪˈlɛktɪv/
US /ɪˈlɛktɪv/
Something you can choose to do but do not have to do.
Art is an elective class, so I picked it because I love drawing.
OTHER MEANINGS
2. A class you choose to take instead of one you must take.
She took an elective in photography last semester.
3. Chosen by voting.
The mayor is an elective official.
4. Having the power to choose.
The committee has an elective role in deciding the winner.