8
discretionary(adjective, open, free, choice, voluntary)
7
elective(adjective, open, free, choice, able)
7
optional(adjective, choice, possible, voluntary, elective)
6
voluntary(adjective, open, free, elective, optional)
2
ability
2
casual
2
contingent
2
discretional(adjective, open, free, voluntary, elective)
2
nonobligatory(adjective, open, free, voluntary, elective)
2
permissive
1
arbitrary(adjective, open, free, voluntary, elective)
1
dispensable
1
enabling
1
free(adjective, open, voluntary, elective)
1
noncompulsory(adjective, open, free, voluntary, elective)
1
not compulsory(expression, adjective, idiom, electoral)
1
not required(expression, adjective, open, free, voluntary)
1
selective(adjective, electoral)
1
tolerated
1
unforced(adjective, open, free, voluntary, elective)
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APASmart Define. (2013). facultative thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/facultative/thesaurus/synonyms
ChicagoSmart Define. 2013. "facultative thesaurus" https://smartdefine.org/facultative/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2013, facultative thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/facultative/thesaurus/synonyms>.
MLASmart Define. "facultative thesaurus" 28 June 2013. Web. 20 September 2026. <https://smartdefine.org/facultative/thesaurus/synonyms>