nah mean

A contraction of knowwhaddamean, itself a contraction of do you know what I mean; from *kno’ what Ah mean, an AAVE variant, which became *kno’ wha’ ah mean > *kno’ ’a’ ah mean, then finally *kna’ ah mean, which is spelled nah ah mean or nah mean, the former of which represents the actual pronunciation more faithfully, but is less commonly used (especially so by AAVE speakers themselves, who prefer the latter form). Equivalent to kn[ow] [wh]a[t] Ah mean.

来源：wiktionary