That can prevail, able to prevail; (originally) †efficacious; capable of being beneficially used (obsolete); (later) able to be used or accepted widely or generally.
Origin
Early 17th century; earliest use found in John Gee (1596–1639). From prevail + -able.
Definition of prevailable in US English:
prevailable
adjectiveprɪˈveɪləbl
rare
That can prevail, able to prevail; (originally) †efficacious; capable of being beneficially used (obsolete); (later) able to be used or accepted widely or generally.
Origin
Early 17th century; earliest use found in John Gee (1596–1639). From prevail + -able.