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pyrogallol py·ro·gal·lol (pī'rō-gāl'ôl', -ōl', -gô'lôl', -lōl')
A white, toxic crystalline phenol used as a photographic developer and to treat certain skin diseases. Also called pyrogallic acid.
an organic compound belonging to the phenol family, used as a photographic film developer and in the preparation of other chemicals