Horse's ass American vulgar slang
Used to refer to someone who is stupid or incompetent
I felt like a horse’s ass when nobody got my joke.
Don't be such a horse's ass!
He thinks he is being cool, but actually he is just acting like a horse’s ass.
To have no money
Used to describe someone who is naive, gullible, inexperienced, easily fooled, ignorant, unsophisticated, etc.
To say, or believe something or someone that seems completely crazy, delusional, or stupid
A person who is low-witted or stupid
To be extremely stupid; not to be alert
The slang dates form the early 19th century.
Used to refer to a intelligent or smart person
If you're such a clever clogs, beat him in this chess game.