preventative preventative /priːˈvɛntətɪv/

adjective

1. Preventing or contributing to the prevention of disease  ( preventative , prophylactic , preventive )
   preventing or contributing to the prevention of disease
    Preventive medicine
   preventive medicine
    Vaccines are prophylactic
   vaccines are prophylactic
    A prophylactic drug
   a prophylactic drug
   
2. Tending to prevent or hinder  ( preventative , preventive )
   tending to prevent or hinder
   

noun

1. An agent or device intended to prevent conception  ( birth control device , preventative , preventive , contraceptive , contraceptive device , prophylactic device )
   an agent or device intended to prevent conception
     She visited the doctor to discuss contraceptive options.
   She visited the doctor to discuss contraceptive options.
   
2. Any obstruction that impedes or is burdensome  ( encumbrance , hinderance , hindrance , hitch , incumbrance , interference , preventative , preventive )
   any obstruction that impedes or is burdensome
   
3. Remedy that prevents or slows the course of an illness or disease  ( preventative , preventive , prophylactic )
   remedy that prevents or slows the course of an illness or disease
    The doctor recommended several preventatives
   the doctor recommended several preventatives