Source : Webster's Revised Unabridged Dictionary (1913)

Rubberize \Rub"ber*ize\, v. t.
   To coat or impregnate with rubber or a rubber solution or
   preparation, as silk.

Source : WordNet®

rubberize
     v : coat or impregnate with rubber; "rubberize fabric for rain
         coats" [syn: {rubberise}, {rubber}]