The Collaborative International Dictionary of English v.0.48:
Naphthoquinone \Naph`tho*qui"none\, n. [Naphthalene + quinone.] (Chem.) A yellow crystalline substance, C10H6O2, analogous to quinone, obtained by oxidizing naphthalene with chromic acid. [1913 Webster]WordNet (r) 3.0 (2006):
naphthoquinone n 1: a fat-soluble vitamin that helps in the clotting of blood [syn: vitamin K, naphthoquinone, antihemorrhagic factor]