Source : Webster's Revised Unabridged Dictionary (1913)

Polymerize \Pol"y*mer*ize\, v. t. (Chem.)
   To cause polymerization of; to produce polymers from; to
   increase the molecular weight of, without changing the atomic
   proportions; thus, certain acids polymerize aldehyde.

Polymerize \Pol"y*mer*ize\, v. i. (Chem.)
   To change into another substance having the same atomic
   proportions, but a higher molecular weight; to undergo
   polymerization; thus, aldehyde polymerizes in forming
   paraldehyde.

Source : WordNet®

polymerize
     v 1: cause (a compound) to polymerize [syn: {polymerise}]
     2: undergo polymerization [syn: {polymerise}]