n.
Pronunciation: kwi- ' n ō n, ' kwi- ˌ
Function: noun
Etymology: International Scientific Vocabulary quin ine + -one
Date: 1853
1 : either of two isomeric cyclic crystalline compounds C 6 H 4 O 2 that are derivatives of benzene
2 : any of various usually yellow, orange, or red quinonoid compounds including several that are biologically important as coenzymes, hydrogen acceptors, or vitamins