look up any word, like dirty sanchez:
 
1.
super moist ass crack
after working all day in the cotton fields I got a bad case of the smac.
by Dan V. February 13, 2007
 
2.
Super-Mega-Awsome-Cool

Used as a name, or an adjective.

Can also be an insult

i.e -
Super-Majourly-Ass-Creepy
Good version ~
Girl 1: Wow, that car was so smac .
Girl 2: Agreed, total smac back .

Or bad version ~
Girl 1: Omg, she is so smac .
Girl 2: I know aye ! Stalker much?
by EmmAndCee March 15, 2010
 
3.
A shortened way of saying Southern Maryland Athletic Conference.
Boy -"I went to Southern Maryland...man those dudes from SMAC are fresh..."
by Swag Swag November 08, 2010
 
4.
Subsequent Mentally Abhorrent Condition
Scenario 1
You: Your sister gave me a SMAC when I walked in on her in the shower.

Friend: Good, your an idiot. Hopefully it was with her ring hand.

You: No dude, a Subsequent Mentally Abhorrent Condition. That bitch has salami tits.

Scenario 2
You: Man, your new girlfriend gave me a SMAC when I saw her on the beach yesterday. What do you feed that woman?

Friend: Yeah dude, shes like a big fluffy teddy bear, but shes got a good heart.

You: There is no way anyone could have enough personality to make up for that. But hey, whatever floats your boat man.

Friend: Thick chicks need dick too breh.
by Zantarus March 15, 2014
 
5.
Another word for a girl snowboarder that is far from a snow bunny. She has a new bruise every day when she gets home from the Star ski hill because she aint scared to try new shit, even in front of the Scenester boarders. This girl is a go-getter, and she killllsss it every time.
Dude, Smac fuckin kills it! She owned in that rail jam last night
by aids davidsooon February 18, 2008
 
6.
To talk shit on someone
"that ho is talkin smac on me"
by Michellle June 27, 2006