Open English Wordnet
Nouns
(n)preventive, preventative, prophylacticremedy that prevents or slows the course of an illness or disease“the doctor recommended several preventatives”
Adjectives
(s)contraceptive, prophylactic, antifertilitycapable of preventing conception or impregnation“contraceptive devices and medications”
(s)cautionary, prophylacticwarding off“the swastika...a very ancient prophylactic symbol occurring among all peoples” (Victor Schultze)
(s)preventive, preventative, prophylacticpreventing or contributing to the prevention of disease“preventive medicine”, “vaccines are prophylactic”, “a prophylactic drug”