hot to an extreme degree; unbearable or intolerable heat, also as related to sexual desire, i.e. very horny
Man, I'm hotter than a half-fucked fox in a forest fire (usually expressed by a female) Meaning in this sense could be duplicitous, as in hot in the literal sense, or hot as in dripping wethorny.
Exactly as the name suggests. This person is so incredibly stupid, that he has no understanding of anything whatsoever, therefore making this person nothing else but a waste of oxygen.