3
unofficial
3
unsanctioned(adjective, legal)
3
wildcat(wrong, irregular, senseless, unwarranted, illegal)
2
adulterated(adjective, deception, inferior)
2
affected(adjective, fake, false, counterfeit, phony)
2
apocryphal(fake, false, bogus)
2
artificial(fake, false, bogus)
2
assumed(fake, false, bogus)
2
by-blow
2
corrupt(adjective, wrong, illegal, unlawful)
2
debased
2
dishonest(adjective, illegal, unlawful, prohibited, banned)
2
dishonorable
2
ersatz(fake, false, bogus)
2
extramarital
2
fake(adjective, false, inferior, bogus)
2
faked(fake, false, bogus)
2
fallacious
2
forged(fake, false, bogus)
2
illogical
11 years ago|17k views|share |citing 
APASmart Define. (2015). illegitimate thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/illegitimate/thesaurus/synonyms
ChicagoSmart Define. 2015. "illegitimate thesaurus" https://smartdefine.org/illegitimate/thesaurus/synonyms (accessed September 24, 2026).
HarvardSmart Define 2015, illegitimate thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/illegitimate/thesaurus/synonyms>.
MLASmart Define. "illegitimate thesaurus" 10 April 2015. Web. 24 September 2026. <https://smartdefine.org/illegitimate/thesaurus/synonyms>