Pec sag. Share definition Flag A condition when a man's pectoral muscles sag down his chest. (usually mistaken for actual physical fitness by females) Jenny: That guy looks totally ripped! Sam: Naw, that's just pec sag. Pec sag. by Dyamn! January 1, 2010 0 0 Get merch Get the Pec sag. mug. Buy Now — $32.95 See more merch
