n. pl. sen·si·tiv·i·ties 1. a. The quality or condition of being sensitive: sensitivity to the concerns of others.
b. The capacity to respond to changes in the environment.
2. The degree of response of a receiver or instrument to an incoming signal or to a change in the incoming signal, as in FM radio.
3. The degree of response to light, especially to light of a specified wavelength, as in photographic film.
4. The proportion of individuals in a population with a particular disease or condition that are correctly identified when administered a test for that disease or condition.
5. Biology The response or degree of response, as of a cell, tissue, or organism, to a chemical substance or stimulus, such as a toxin, infectious agent, hormone, allergen, or antigen: insulin sensitivity.