Definition of "naphthol" [naph•thol]

• An organic compound, C10H7OH, occurring in two isomeric forms, alpha-naphthol and beta-naphthol. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "They are also called naphthol colours from the use of beta-and alpha-naphthol in their production."
• "Now the diazo compounds are rather unstable bodies, but they have a great affinity for other compounds, such as naphthol, phenylene diamine, phenol, and combine easily with them when brought into contact with them."
• "In 1869 and 1870 he was assistant to H. Wichelhaus in Berlin, with whom he worked on the nitration of b-naphthol."