quaternary ammonium compound

WordReference Random House Unabridged Dictionary of American English © 2025

quat′ernary ammo′nium com′pound, [Chem.]

1. Chemistry any of a class of salts derived from ammonium in which the nitrogen atom is attached to four organic groups, as in benzalkonium chloride;
   the salts are cationic surface-active compounds used as antiseptics and disinfectants. Also called quat′ernary ammo′nium salt′. 

• 1815–25