1.nounAn individual skilled in the art of seduction using verbal skills.
"She left with him; he must be a true mack."
2.nounA raincoat or mackintosh.
3.nounAn element of a ship's superstructure which places the function of a ship's mast on its exhaust stack, adding the skeletal supporting structure to the smokestack to support the mast's complement of functions.