superlative (adj.)

late 14c., from Old French superlatif "absolute, highest; powerful; best" (13c.) and directly from Late Latin superlativus "extravagant, exaggerated, hyperbolic," from Latin superlatus "exaggerated" (used as past participle of superferre "carry over or beyond"), from super "beyond" (see super-) + lat- "carry," from *tlat-, past participle stem of tollere "to take away" (see extol). Related: Superlatively; superlativeness.

The noun is attested from 1520s, originally in the grammatical sense, "a word in the superlative;" hence "exaggerated language" (1590s).