What is "to funk out"

Funk \Funk\, v. i.

1. To emit an offensive smell; to stink.

2. To be frightened, and shrink back; to flinch; as, to funk at the edge of a precipice. [Colloq.]
   --C. Kingsley.

   To funk out, to back out in a cowardly fashion. [Colloq.]

   To funk right out o' political strife.
   --Lowell (Biglow Papers).