doesn't/wouldn't know (one's) ass from (one's) elbow

(redirected from doesn't/wouldn't know ass from elbow)

doesn't/wouldn't know (one's) ass from (one's) elbow

rude slang Is very stupid or dimwitted. I'm not surprised to hear that she got lost two blocks away from her house—she doesn't know her ass from her elbow.
See also: ass, elbow, know