adjective: (linguistics) In linguistics, particularly Indo-European Studies, signifying a stem which alternates between more than one form when declined for grammatical case. Examples of heteroclitic noun stems in Proto-Indo-European include *wod-r/n- "water" (nominoaccusative *wódr; genitive *udnés; locative *udén) and *yékʷ-r/n- "liver" (nominoaccusative *yékʷr, genitive *ikʷnés). In Proto-Indo-European, heteroclitic stems tend to be noun stems with grammatically inanimate gender.
adjective: (microbiology) Pertaining to antibodies that react to a wide variety of antigens.
