Naphthalic

Part of speech: adjective

Definitions

1. Relating to or derived from naphthalene, a white crystalline hydrocarbon used in chemical manufacturing and dyes
2. Describing a chemical compound that contains or is obtained from naphthalene, the aromatic hydrocarbon found in coal tar
3. Pertaining to substances made from naphthalene, such as the acid derivatives used in producing dyes and resins

Etymology: "Naphthalic" is a chemistry term built in English from "naphthalene" plus the adjectival suffix "-ic", so its story runs through the older word it hangs on. The first part, "naphtha," goes back through Latin and Greek to Akkadian and Old Persian: the Greek "náphtha" named a flammable, oily substance, the kind of petroleum-like liquid that ancient peoples knew seeping from the ground. English took the stem as "naphth(a)," and chemists later attached the suffix "-ene" (borrowed through French) to make "naphthalene," the name for a hydrocarbon distilled from coal tar. The final syllable, "-ic," has a long pedigree of its own. It descends from a Latin adjectival ending "-icus," which passed through Old French "-ique" into Middle English as "-ik," and eventually settled into the spelling "-ic." Attached to "naphthalene," it produces an adjective describing compounds derived from or containing that substance, a deliberately technical formation that chemists used to name whole families of related compounds.