v. t. to rendered insensitive or less sensitive. Opposite of sensitize.
adj. rendered insensitive.
v. t. (Photog.) To render sensitive, or susceptible of being easily acted on by the actinic rays of the sun;
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 ]