adjective, sometimes rap·id·er, rap·id·est.
- occurring within a short time; happening speedily: rapid growth.
- moving or acting with great speed; swift: a rapid worker.
- characterized by speed: rapid motion.
- Usually rapids. a part of a river where the current runs very swiftly.
- (of an action or movement) performed or occurring during a short interval of time; quicka rapid transformation
- characterized by high speedrapid movement
- acting or moving quickly; fasta rapid worker
1630s, “moving quickly,” from French rapide (17c.) and directly from Latin rapidus “hasty, swift, rapid; snatching; fierce, impetuous,” from rapere “hurry away, carry off, seize, plunder,” from PIE root *rep- “to snatch” (cf. Greek ereptomai “devour,” harpazein “snatch away,” Lithuanian raples “tongs”). Meaning “happening in a short time” is from 1780. Related: Rapidly; rapidness. Rapid-transit first attested 1852, in reference to street railways; rapid eye movement is from 1906.