Webster's Revised Unabridged Dictionary · 1913

Hydroquinone

Hydroquinone , noun

[Hydro-, 2 + quinone.]

(Chemistry) A white crystalline substance, C6H4(OH)2, obtained by the reduction of quinone. It is a diacid phenol, resembling, and metameric with, pyrocatechin and resorcin. Called also dihydroxy benzene.