A bitch in heat is sometimes used when reffering to humans, generally females. A female ththat goes after every male she can find, and is being extremely lustful. A blunt way to put this would be a horny woman.
"She was eyeing the man like a bitch in heat."
(Or sometimes it is written as "like a bitch DOG in heat.")
2) A dishonest/ lying person; comes from the old southern expression: "You lie like a dog(or bitch) in heat." (Female dogs lie around a lot when in heat)
- The phrase is used as an emphatic tool; it has a kind of harsh connotation, like putting damn in front the word "liar."
The phrase's use is not limited to describing women: "You lie like a bitch in heat son."
Joe: Sarah doesn't want to talk to me. Think I should be sensitive and aske her what's wrong?
John: Fuck no, she's obviously just a bitch in heat