Synonyms for Contraceptive (same or very similar meaning)
WordNet sense 1 (an agent or device intended to prevent conception):
preventative, preventive, contraceptive device, birth control device, prophylactic deviceWordNet sense 2 (capable of preventing conception or impregnation):
prophylactic, antifertilityWordNet sense 3 (intended or adapted to afford protection of some kind):
protectiveFrom the ODE community, based on WordNetadd/edit