D defs.my
Entry 1 sense Webster, 1913

Preventative

/prēv-ĕn'-tət-ĭv/ · Pre·vent·a·tive · IPA /pɹɪˈvɛntətɪv/
01 n. That which prevents; -- incorrectly used instead of preventive.
  1. 1.
    That which prevents; -- incorrectly used instead of preventive.