: resembling quinone especially in having a 6-membered carbon ring containing two double bonds

Word History

First Known Use

1878, in the meaning defined above

Time Traveler
The first known use of quinonoid was in 1878

Browse Nearby Words

Cite this Entry

“Quinonoid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/quinonoid. Accessed 8 Jul. 2026.

Medical Definition

: resembling quinone
especially : having a structure characterized by a benzene nucleus containing two instead of three double bonds within the nucleus and two external double bonds attached to the nucleus either at ortho or para positions (as in the two carbonyl groups of quinones)
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster