late 14c., from Old French superlatif (13c.), from Late Latin superlativus "exaggerated, superlative," 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). The noun is attested from 1520s, originally in the grammatical sense.
The form of an adjective indicating the greatest degree of the quality that the adjective describes. Best is the superlative form of good; fastest is the superlative form of fast; most charming is the superlative form of charming. The usual superlative takes the ending -est. (Compare comparative.)