quaternary ammonium compoundquaternary ammonium compound
any of a class of compounds in which the four hydrogen atoms of the ammonium radical are replaced by other groups, generally organic radicals: used as solvents, disinfectants, etc.
quaternary ammonium compound
Any of a group of compounds composed of a cation, in which a central nitrogen atom is joined to four organic groups, and any of various anions, used as antiseptics, solvents, and emulsifying agents.
(plural quaternary ammonium compounds)