desensitize

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.