noun
: a colorless gas N 2 O that is obtained usually by heating ammonium nitrate, that when inhaled produces incoordination of movement and loss of sensibility to pain preceded by exhilaration and sometimes laughter, and that is used chiefly as an anesthetic (as in dentistry) and in preparing whipped cream and other food aerosols; di-nitrogen monoxide — called also laughing gas, nitrogen(I) oxide