I. |fēnō+ noun
Etymology: International Scientific Vocabulary phen- + thiazine
: a greenish yellow crystalline compound C 12 H 9 NS that is formed by heating diphenylamine with sulfur, that is an anthelmintic and insecticide, and that is used chiefly in veterinary practice to rid farm animals of internal parasites — called also thiodiphenylamine ; compare structural formula
II. noun
: any of various phenothiazine derivatives (as chlorpromazine) that are used as tranquilizing agents especially in the treatment of schizophrenia