ˈpentəˌnōn noun
( -s )
Etymology: pentane + -one
: either of two isomeric flammable liquid ketones derived from normal pentane:
a. : the unsymmetrical compound CH 3 CH 2 CH 2 COCH 3 — called also methyl propyl ketone, 2-pentanone
b. : the symmetrical compound (C 2 H 5 ) 2 CO obtainable from propionic acid — called also diethyl ketone, 3-pentanone, propione