-sə(r) noun
( -s )
1. : one that reduces
2.
a. : one that condenses or consolidates
b. : one that makes smaller or less: as
(1) : reducing coupling
(2) : reducing valve
(3) : a hydraulic device that lowers pressure and increases movement used to transmit the load from the hydraulic support of the lower shackle to the lever weighing apparatus in some kinds of heavy testing machines
(4) : shell reducer
3. : one that weakens or dilutes: as
a. : reducing agent ; specifically : one used in photographic development
b. : a chemical solution for reducing the density of a silver image in photography
c. : a paint thinner
d. : a vessel or apparatus in which chemical reduction is carried out : reductor
e. : a worker who adds thinners to paint or varnish to obtain the proper consistency
4. : one that processes especially for commercial use
a reducer of iron ore