one of the cycloparaffins, CH, present in petroleum: used as a solvent, paint remover, etc.
See cyclohexane in American Heritage Dictionary 4
cy·clo·hex·ane
noun
An extremely flammable, colorless, mobile liquid, C6H12, obtained from petroleum and benzene and used in the manufacture of nylon and as a solvent, a paint, and a varnish remover.