Contrary to accepted morality (especially sexual morality) or convention.

Contrary to or forbidden by law:
— Illicit trade.

synonyms: illegitimate, outlaw, outlawed, unlawful.

Roget 925: undue; unlawful etc. (illegal) 964; unconstitutional; illicit; unauthorized, unwarranted, disallowed, unallowed^†, unsanctioned, unjustified; unentitled^†, disentitled, unqualified, disqualified; unprivileged, unchartered.    illegitimate, bastard, spurious, supposititious, false; usurped.    tortious [Law].    undeserved, unmerited, unearned; unfulfilled.    forfeited, disfranchised.    improper; unmeet, unfit, unbefitting, unseemly; unbecoming, misbecoming^†; seemless^†; contra bonos mores [Lat.]; not the thing, out of the question, not to be thought of; preposterous, pretentious, would-be.    ... show more

Roget 964: illegal [contrary to law], unlawful, illegitimate; not allowed, prohibited etc. 761; illicit, contraband; actionable.    unwarranted, unwarrantable; unauthorized; informal, unofficial; injudicial^†, extrajudicial.    lawless, arbitrary; despotic, despotical^†; corrupt, summary, irresponsible; unanswerable, unaccountable.    [of invalid or expired law] expired, invalid; unchartered, unconstitutional; null and void; a dead letter.    [in absence of law] lawless, unregulated ... show more

Polish: bezprawny