short for saying most definitely, or sure.
Yo you gonna be at the party tonight?" Jarel: "Mos def bro.
by 92Prodigy April 8, 2011
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a bastardization of most definately
usually used in online lingo
A: hey
B: wuzup
A: n2mh u
A: ssdd
A: wanna see a movie
B: mos def
by cait/eileen January 30, 2003
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(N.) When you reach the maximum of not being able to hear.
"Yo, I don't think that D-Bo heard me. He must be Mos Def now."
by G-Union October 21, 2003
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short for most definetly!!!!
tyler: Did it feel the best when i put it in your butt last night?

zane: mos def!
by jake1234 April 4, 2006
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Mos Def comes from two words, mos is short slang for "most" and def is short for "deft" which means skilled. Thus "mos def" is defined as "most skilled."
Mos Def is also a rap alias for one Dante Smith.
by RTK666 December 28, 2005
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