Source : Webster's Revised Unabridged Dictionary (1913)

Illegalize \Il*le"gal*ize\, v. t. [imp. & p. p. {Illegalized};
   p. pr. & vb. n. {Illegalizing}.]
   To make or declare illegal or unlawful.

Source : WordNet®

illegalize
     v : declare illegal; outlaw; "Marijuana is criminalized in the
         U.S." [syn: {outlaw}, {criminalize}, {criminalise}, {illegalise}]
         [ant: {legalize}, {legalize}, {legalize}]