To render sensitive, or susceptible of being easily acted on by the actinic rays of the sun; as, sensitized paper or plate.
- To make sensitive: "The polarity principle . . . sensitizes the observer to the coexistence of seemingly contradictory phenomena” ( Heinz Eulau).
- To make (a film or plate) sensitive to light, especially to light of a specific wavelength.
- To make hypersensitive or reactive to an antigen, such as pollen, especially by a second or repeated exposure.
- To become sensitive or hypersensitive.