1. a phrase used as a declaration or recognition of greatness by oneself or another person, most often used in a congratulatory nature

2. an informal greeting between friends, replaces or adds on to "yo" to mean "hows it going", or "whats up"

3. a response to a greeting, and depending on vocal tones, can be used to convey a wide variety of moods

4. nonsensical lyrics used by Beanie Man at the beginning of the song Who Am I
Example 1:
Dude 1: Yo dude, remember that girl I was talking to at the club last night?
Dude 2: Yea.
Dude 1: Well afterward we went back to my place and she let me tap that!
Dude 2: Sim simmaaaaa!

Example 2+3:
Dude 1: Yo, sim simma?
Dude 2: Sim simma.

Example 4:
Beanie Man: Sim simma, who got the keys to my Bimmer?
by Halo 2 Killa December 22, 2008
Get the sim simma mug.