in·cit·ant I. \ə̇nˈsītənt\adjective Etymology: Latin incitant-, incitans, present participle of incitare to incite : inciting, causative, stimulating < incitant of infection > < an incitant factor > II. noun (-s) : an inciting agent; especially: a factor (as an infective agent) that is the essential causative agent of a particular disease < where the fungal incitant is present mildew is likely to damage foliage in cold wet weather >