Rapid synonyms such as breakneck, abrupt, and alacritous. Rapid is an adjective, and its antonyms are slow and leisurely. Additionally, here are 34 synonyms, related words, and verbs for rapid.
abrupt, alacritous, breakneck, brisk, expeditious, express, fast, fast-track, fleet, fleeting, flying, hasty, headlong, high-speed, hurried, immediate, instant, instantaneous, lightning, lively, meteoric, overnight, p.d.q. (pretty damn quick), precipitate, prompt, quick, sharp, speedy, sudden, swift, volant, whirlwind, and whistle-stop.