The Collaborative International Dictionary of English v.0.48:

Mace \Mace\, prop. n. [Trademark.]
   A chemical preparation containing tear gas in a solvent,
   packaged in the form of a spray, and used to temporarily
   incapacitate people, such as rioters or criminals, by causing
   intense eye and skin irritation; also called chemical mace.
   It is designed to be a non-lethal weapon for defending
   against violent people.
   [PJC] macebearer

WordNet (r) 3.0 (2006):

Chemical Mace
    n 1: (trademark) a liquid that temporarily disables a person;
         prepared as an aerosol and sprayed in the face, it
         irritates the eyes and causes dizziness and immobilization
         [syn: Mace, Chemical Mace]