[′meth·əl ¦en ¦am·əl ′kē‚tōn] (organic chemistry) CH3(CH2)4COCH3 Stable, water-white liquid; miscible with organic lacquer solvents, slightly soluble in water; used as an inert reaction medium and as a solvent for nitrocellulose lacquers. Also known as 2-heptanone.