'Sensitizer' definitions:

Definition of 'sensitizer'

From: WordNet
noun
(chemistry) a substance other than a catalyst that facilitates the start of a catalytic reaction [syn: sensitizer, sensitiser]

Definition of 'Sensitizer'

From: GCIDE
  • Sensitizer \Sen"si*ti`zer\, n. (Photog.) An agent that sensitizes. [1913 Webster]
  • The sensitizer should be poured on the middle of the sheet. --Wilis & Clements (The Platinotype). [1913 Webster]