noun one of several volatile inflammable liquids obtained by the distillation of certain carbonaceous materials and resembling the naphtha from petroleum; as, boghead naphtha, from boghead coal (obtained at boghead, scotland); crude naphtha, or light oil, from coal tar; wood naphtha, from wood, ·etc.
2. naphtha ·noun the complex mixture of volatile, liquid, inflammable hydrocarbons, occurring naturally, and usually called crude petroleum, mineral oil, or rock oil. specifically: that portion of the distillate obtained in the refinement of petroleum which is intermediate between the lighter gasoline and the heavier benzine, and has a specific gravity of about 0.7, used as a solvent for varnishes, as a carburetant, illuminant, ·etc.