0
obligate aerobe(expression, idiom, life)
0
obligate anaerobe(expression, idiom, life)
0
occasional
0
open(free, voluntary, elective)
0
opportune
0
possible(voluntary, elective)
0
promising
0
propitious
0
random
0
sanctioning
0
selection
0
spontaneous
0
suffered
0
suitable
0
supporting
0
supportive
0
thereof
0
uncoerced
0
uncompelled(voluntary, elective)
0
uncompulsory
13 years ago|2.1k views|share |citing 
APASmart Define. (2013). facultative thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/facultative/thesaurus/synonyms
ChicagoSmart Define. 2013. "facultative thesaurus" https://smartdefine.org/facultative/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2013, facultative thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/facultative/thesaurus/synonyms>.
MLASmart Define. "facultative thesaurus" 28 June 2013. Web. 21 September 2026. <https://smartdefine.org/facultative/thesaurus/synonyms>