A frequently used phrase among slack jawed rappers.
(I've never met one that wasn't slack jawed)
Due to the fact that they can't communicate well because of the stupidity of ebonics.

It is primarily used to ask if the recipient of a statement understands what was being spoken. It is necessity to ask this because rappers are to stupid to ask what the speaker meant when they couldn't understand the statement.
you know what i'm sayin homie DUH!!!
by RAPSUCKS1738 November 17, 2006
Get the you know what i'm sayin mug.