- reducing agent, reducer, reductant - a substance capable of bringing about the reduction of another substance as it itself is oxidized; used in photography to lessen the density of a negative or print by oxidizing some of the slackened silver
--1 is a kind of chemical agent
--1 has particulars: hydrazineDerived form: verb reduce10 - reducer - pipefitting that joins two pipes of different diameter
--2 is a kind of pipefitting, pipe fitting