Il*lic"it*ly

from The Collaborative International Dictionary of English v.0.48

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]