naphthalene n.

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.

word-forming element in chemistry, often interchangeable with -in (2), though modern use distinguishes them; early 19c., from French -ine, the suffix commonly used to form words for derived substances, hence its extended use in chemistry. It was applied unsystematically at first (as in aniline), but now has more restricted use.

The French suffix is from Latin -ina, fem. form of -inus, suffix used to form adjectives from nouns, and thus is identical with -ine (1).