Pronunciation: (sen"si-tu-zā'shun),[key] —n. 1. the state or process of being sensitized.
2. Psychol.the process of becoming susceptible to a given stimulus that previously had no effect or significance.
3. Immunol. a. a state or condition in which a previously encountered foreign substance triggers an immune reaction.
b. an immunologic state or condition that is evidenced by the acquired ability of a cell or individual to detect the presence of a foreign substance upon reexposure to the substance and to react immunologically.