Rapid1. (a.) Very swift or quick; fast; as, a rapid stream; a rapid flight; a rapid motion.
2. (a.) Advancing with haste or speed; speedy in progression; in quick sequence; as, rapid growth; rapid improvement; rapid recurrence; rapid succession.
3. (a.) Quick in execution; as, a rapid penman.
4. (n.) The part of a river where the current moves with great swiftness, but without actual waterfall or cascade; -- usually in the plural; as, the Lachine rapids in the St. Lawrence.
Thesaurus Entries
abrupt, agile, alacritous, bluff, bold, breakneck, brisk, ceaseless, chattering, chute, constant, continual, dashing, double-quick, eagle-winged, expeditious, express, fast, fleet, flying, galloping, hair-trigger, hasty, headlong, high-speed, hurried, hustling, immediate, impetuous, incessant, instant, instantaneous, light of heel, light-footed, lively, machine gun, mercurial, nimble, nimble-footed, oscillating, perennial, perpetual, plunging, precipitate, precipitous, prompt, pulsating, quick, quick as lightning, quick as thought, rapids, reckless, regular, repeated, riff, riffle, ripple, running, sault, sharp, sheer, shoot, snappy, spanking, speedy, staccato, steady, steep, stuttering, sudden, sustained, swift, unbroken, unceasing, unchanging, unintermitted, unintermittent, unintermitting, uninterrupted, unremitting, unstopped, unvarying, vertical, vibrating, winged