v. To render insensitive or less sensitive.v. Immunology To make (an individual) nonreactive or insensitive to an antigen.v. To make emotionally insensitive or unresponsive, as by long exposure or repeated shocks: "This movie in effect may resensitize people who thought they were desensitized to violenceā ( Steven Spielberg). v. To make (a photographic film or substance) less sensitive to light.