Any one of the three metameric hydrocarbons, C5H12, of the methane or paraffin series. They are colorless, volatile liquids, two of which occur in petroleum. So called because of the five carbon atoms in the molecule.
a hydrocarbon gas with the formula C5H12 that is sometimes used as a bottled fuel gas. Calibration of Gaz de France explosimeters are claimed to be to pentane gas. Actually, GdF units include a 100% safety factor based on the pentane LEL cur.