preventer

transitive verb

1. Obsolete
   1. to act in anticipation of (an event or a fixed time)
   2. to anticipate (a need, objection, etc.)
   3. to precede
2. to stop or keep (from doing something)
3. to keep from happening; make impossible by prior action; hinder

Origin: ME preventen < L praeventus, pp. of praevenire, to anticipate < prae-, before (see pre-) + venire, to come

intransitive verb