As coined by the
legendary rapper himself, "Mos-Def" refers to a thing, person, experience etc which is "mos" (or most, hugely, a lot), "def" (excellent, awesome; NOT
short for 'definitely').
Mos-Def's changing his rap name to "Yasiin"??
Don't
sweat it, he's still the MOS DEF
rapper out.... after Chuck D of course..