to lessen the sensitiveness of.

to make indifferent, unaware, or the like, in feeling.

Photography . to make less sensitive or wholly insensitive to light, as the emulsion on a film.

Printing . to treat (the design on a lithographic plate) with an etch in order to increase the capacity to retain moisture, and to remove traces of grease.

Chemistry . to reduce the sensitivity of (an explosive) to those stimuli capable of detonating it.

verb

anesthetize , benumb , deaden , make inactive , make less sensitive , numb , render insensible , blunt , dull