py·ro·cat·e·chol 
(pī′rō-kătĭ-kôl′, -kŏl′, -kōl′)
(pī′rō-kătĭ-kôl′, -kŏl′, -kōl′)n.
A biologically important phenol, C6H6O2, having two hydroxyl groups attached to the benzene ring, used in dyeing, tanning, photography, and as an antiseptic. Also called catechol.