In close association with macking, recieving/performing sexual acts, usually only referred to when drunk or at a party, or the day after.
by Colleen September 08, 2004
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.
by mack_in_training December 10, 2009