An apparatus for the reduction of ferric to ferrous sulphate by means of zinc: used in the analysis of iron and steel.(noun)
The Century Dictionary (Public Domain)
Use "reductor" in a sentence
"It was absurd that the Cuban people, who own more than 150 sugar mills, had to start a sugar harvest without a centrifuge, a vacuum pump, a speed reducing device [reductor de velocidad] and so forth."