Wiktionary
defeatable
a. (context rare English) Capable of being defeated.
Usage examples of "defeatable".
She wasn’t like any of the other monsters out of folklore, defeatable with silver bullets or crucifixes.
At his own game, he would make no errors of any kind, and he would be defeatable only through circumstances beyond his control The best example"-Korita was suave-"is the highly trained human being of our own era.