Best definition
One who has no physical strength, and wouldn’t win in a fight.

That guy couldn’t even kill a ladybug, that weakass.
weakass: define #2
weak ass
someone who hasen’t got a propa ass!
ooooh he’s fit, oh wait for it there had to be a flaw! hes got a weak ass man!

(kinda flat and not too much on the pert side either lol)