'Illicit' definitions:

Definition of 'illicit'

From: WordNet
adjective
Contrary to accepted morality (especially sexual morality) or convention; "an illicit association with his secretary" [ant: licit]
adjective
Contrary to or forbidden by law; "an illegitimate seizure of power"; "illicit trade"; "an outlaw strike"; "unlawful measures" [syn: illegitimate, illicit, outlaw(a), outlawed, unlawful]

Definition of 'Illicit'

From: GCIDE
  • Illicit \Il*lic"it\, a. [L. illicitus; pref. il- not + licitus, p. p. of licere to be allowed or permitted: cf. F. illicite. See In- not, and License.] Not permitted or allowed; prohibited; unlawful; as, illicit trade; illicit intercourse; illicit pleasure. [1913 Webster]
  • One illicit . . . transaction always leads to another. --Burke. -- {Il*lic"it*ly}, adv. -- {Il*lic"it*ness}, n. [1913 Webster]