the thought in your head and/or the state of your mind after someone has been merkedhardcore
bob1: that was some serious merkage!
bob2: thats exactly what i was thinking too homie!
bob1: what?
bob2: i dont know, what did i just say?
bob1: forget it just pass me that blunt
The noun form of the verb to mack, ie. hit on chicks, or the scalar (measurable) quantity thereof. The standard unit of macking is Neils (after Neil Patrick Harris' epitome of macking in his portrayal of Barney Stinson in HIMYM) and the imperial unit is Don Juans.
That girl is going to need some serious mackage before she loosens up.