/kwi nohn", kwin"ohn/ , n. Chem.
1. a yellow, crystalline, cyclic unsaturated diketone, C 6 H 4 O 2 , formed by oxidizing aniline or hydroquinone: used chiefly in photography and in tanning leather.
2. any of a class of compounds of this type.
Also, chinone .
[ 1850-55; QUIN(IC ACID) + -ONE ]