to stop (something) from happening or existing
Both sides took steps to prevent war
(often + from) to hold or keep (somebody or something) back; to stop (somebody or something) from doing something
There's nothing to prevent you from going alone
preventability /-ʹbiliti/ noun
preventable adj
preventer noun
preventible adj
prevention /-sh(ə)n/ noun
[Middle English preventen to anticipate, from Latin praeventus, past part. of praevenire to come before, anticipate, forestall, from prae- + venire to come]