presto (adv.) Look up presto at Dictionary.com
1590s, "quickly," used by conjurers, etc., from Italian presto "quick, quickly" in conjuror's patter, from Latin praestus "ready," praesto (adv.) "ready, available," from prae "before" (see pre-) + stare "to stand," from PIE root *sta- "to stand, make or be firm." Compare Latin praesto esse "to be at hand, be ready," source of French prêt "ready." As a musical direction, it is a separate borrowing from Italian, first recorded 1683.