1570s, from Latin, from Greek naphtha "bitumen," perhaps from Persian neft "pitch," or Aramaic (Semitic) naphta, nephta, but these could as well be from Greek. In Middle English as napte (late 14c.), from Old French napte, but the modern word is a re-introduction. In ancient writers it refers to a more fluid and volatile variety of natural asphalt or bitumen. In modern use, a colorless inflammable liquid distilled from petroleum.
1942, from naphthenic + palmitic, names of the two acids used in manufacture of the chemical thickening agent. See naphtha. It was used especially in mixture with gasoline to make a kind of inflammabvle jelly used in flame-throwers, incendiary bombs, etc. The verb, "to destroy with napalm," is by 1950, from the noun. Related: Napalmed; napalming.
early 15c., "petroleum, rock oil, oily inflammable substance occurring naturally in certain rock beds" (mid-14c. in Anglo-French), from Medieval Latin petroleum, from Latin petra "rock" (see petrous) + oleum "oil" (see oil (n.)). Commercial production and refinement of it began in 1859 in western Pennsylvania, and for most of the late 19th century it was produced commercially almost entirely in Pennsylvania and western New York.
Petroleum was known to the Persians, Greeks, and Romans under the name of naphtha; the less-liquid varieties were called [asphaltos] by the Greeks, and bitumen was with the Romans a generic name for all the naturally occurring hydrocarbons which are now included under the names of asphaltum, maltha, and petroleum. The last name was not in use in classic times. [Century Dictionary, 1895]