Synonyms of illegal

1 Syllable
hot
2 Syllables
heavy, undue, wildcat, banned, smuggled, crooked, unfair, wrongful, taboo, lawless, racket, no-no, tabu, bootleg, shady
3 Syllables
villainous, criminal, unsporting, pirated, contraband, black-market, forbidden, violating, outlawed, felonious, proscribed, verboten, illicit, unlawful
4 Syllables
undeserved, unscrupulous, unlicensed, unwarranted, unapproved, prohibited, extralegal, interdicted, unofficial, irregular, unethical, misbegotten, indictable, unconscientious, actionable
5 Syllables
unwarrantable, unauthorized, prosecutable, under-the-counter, exploitative
6 Syllables
illegitimate, unconstitutional