dif·fer·en·tia \ˌdifəˈrench(ē)ə\noun (pluraldifferenti·ae \-chēˌē\) Etymology: Latin, difference — more at difference 1.: the characteristic or quality that distinguishes one species from others of the same genus; broadly: a distinguishing characteristic < the chief differentiae between man and the brute creation — A.T.Quiller-Couch > 2.: a trope in medieval music