Answer: polymerization.
Justification:
Poly means many, and monomer means parts.
Then, a polymer is a compound made of many smaller molecules, and the process to form a polymer is named polymerization.
Polymers are large molecules formed by the combination of of many repeated units (monomers).
Some polymerization reaction are adition and condensation.
Some very well know polymers are polyethilene, nylon, pvc, polyester, among many other. They are also known as plastics.
