quā̆drŭplĭco, āvi, ātum, 1, v. a. [quadruplex], to multiply by four, make fourfold, quadruplicate: rem suam, one’s property, Plaut. Stich. 3, 1, 4: numerum, Dig. 38, 10, 10.
Hence, adv.: quădrŭplĭcā-tō, four times as much, quadruply (postAug.), Plin. 2, 17, 14, § 76: emptis vineis, id. 14, 4, 5, § 51.