n A long baton used by some drum majors to keep time and lead a marching band. If this baton is referred to as a mace, by convention it has a ceremonial often decorative head, which, if of metal, usually is hollow and sometimes intricately worked.
v To spray in defense or attack with mace (pepper spray, or, formerly, tear gas) using a hand-held device.
v (informal) To spray a similar noxious chemical in defense or attack using an available hand-held device such as an aerosol spray can.