sus·cep·ti·bil·i·ty / səˌseptəˈbilitē/ • n. (pl. -ties) 1. the state or fact of being likely or liable to be influenced or harmed by a particular thing: lack of exercise increases susceptibility to disease. ∎  (susceptibilities) a person's feelings, typically considered as being easily hurt: I was so careful not to offend their susceptibilities.2. Physics the ratio of magnetization to a magnetizing force.

susceptibility (sŭ-sep-ti-bil-iti) n. lack of resistance to disease. It is partly a reflection of genetic factors and general health but is also influenced by vaccination or other methods of increasing resistance to specific diseases.