1. [ noun ] (chemistry) 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
Synonyms: reductant reducing_agent
Related terms: chemical_agent hydrazine deoxidize
2. [ noun ] pipefitting that joins two pipes of different diameter
Related terms: pipefitting
Similar spelling:   Redeker