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4.
Mad as hell. About to lay the smack down on some triflin' bitch.
Them's fighting words. She musta been in heat when she said that about Billy's gimp leg.
by (r)evolution September 06, 2007
 
1.
When a creature (most likely an amimal, but can apply to humans) is so horny, it'll hump anyhthing in sight.
Mona: OMG! Look at Jack!
Mae: What the fuck is he doing?
Jack(pulling out of the dog's ass): Ooooh, yeah! Thanks again, sparky!
Sparky: Woof!
by sexie chocolate October 05, 2004
 
2.
When an animal (humans included) is so horny and eager to mate, that they'll hump whoever comes along.

Some people think that only females experience this state, but male animals also have a reputation for being achingly randy.
"Great...! Just great! We forgot to neuter our cat, and now she's in heat! I can't stand the howling!"

"While in Frankfurt (appropriately), I once asked a German storekeeper for a 'heißer Hund'- literally 'a hot dog.' He burst out laughing, as 'heißer Hund' in German suggests a dog in heat." -Richard Lederer
by Lorelili February 05, 2006
 
3.
Phrase meaning either "bothered", "stressed out", or "completely blown away".
Man, I caught my gurl cheatin' wit some sucka. Dat bitch got me In Heat!!!!!
by Tommie Kemper, Logan Rains November 20, 2007