Definition of naphtha:

part of speech: noun

A variety of bitumen, thin, fluid, and highly inflammable, used largely as a solvent for caoutchouc; rock- oil.

Usage examples:

Word of the day

ronde bosse

In arch., a term applied to sculptured objects in their full forms, in contradistinction to those which are in relief, or attached more or less to a plane or ground. ...