reed mace: see cattail.

mace, in botany and cooking: see nutmeg.

Mace, chemical spray device used by police in riot control. Mace is ordinary tear gas (chloroacetophenone, or CN) in a volatile solvent contained in a spray can. It causes severe lacrimation and temporary blindness. If sprayed directly into the face from a distance of less than 6 ft (1.8 m), it may cause permanent injury.