To have a gun on your person at any given time.
I'm packin heat now that I'm out all night downtown.
by Miklus August 7, 2006
kaia: what is packing heat?
cory: are you serious?
cory: OMg lol
kaia: yes, what does it mean?
cory: to take a dick up the ass
kaia: really? ooh lo
by coryp January 26, 2005
1. The act of carrying a firearm on one's person.

2. When a person is well-endowed. Male: Used when referring to a man who has a large penis. Female: Used when referring to a woman who has large and shapely breasts and/or a large and shapely ass.
"Girl, did you fuck him? Is he packin heat?"

"That girl is stacked up, she's packin heat."
by The Cracka Atacka December 30, 2010
To have a bigger dick than your size suggests.
Mike: Hey man I saw this short old armenian dude buying two boxes of magnums in 7-11 the other day.
Jason: Holy shit, either he's sellin' condoms to the bruthas on the street or he's packin' heat.
by Michael Whalen December 13, 2007