1. adj. meaning "cowardly, wuss-like"
2. A slightly archaic emphasizer for an insult, right up there with "godforsaken" and variations of the word "freakin' "
Used to call someone a coward in ADDITION to another insult.
Jim: That Fred is a jerk!
Bob: He doesn't deserve to be a jerk. He's a yellow-bellied bastard!