Wiktionary
hydroxyanthraquinone
n. (context organic compound English) Any of several organic compounds that can be viewed as derivatives of an anthraquinone through replacement of one hydrogen atom by a hydroxyl group.
Wikipedia
Hydroxyanthraquinone
A hydroxyanthraquinone (formula: CHO(OH)) is any of several organic compounds that can be viewed as derivatives of an anthraquinone through replacement of one hydrogen atom (H) by an hydroxyl group (-OH). The IUPAC nomenclature recommends hydroxyanthracenedione.
Usually "hydroxyanthraquinone" refers to a derivative of 9,10-anthraquinone.