Webster's Revised Unabridged Dictionary · 1913

Pyrocatechin

Pyrocatechin , noun

[Pyro- + catechu.]

(Chemistry) A white crystalline substance, C6H4(OH)2, of the phenol series, found in various plants; -- so called because first obtained by distillation of gum catechu. Called also catechol, oxyphenol. etc.