The Collaborative International Dictionary of English v.0.48:

Phlorone \Phlo"rone\, n. [Phlorol + quinone.] (Chem.)
   A yellow crystalline substance having a peculiar unpleasant
   odor, resembling the quinones, and obtained from beechwood
   tar and coal tar, as also by the oxidation of xylidine; --
   called also xyloquinone.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Xyloquinone \Xy`lo*qui"none\, n. [Xylene + quinone.] (Chem.)
   Any one of a group of quinone compounds obtained respectively
   by the oxidation of certain xylidine compounds. In general
   they are yellow crystalline substances.
   [1913 Webster]