Webster’s Revised Unabridged Dictionary · 1913
Rapid
Rap′id (răp′ĭd), a. [L. rapidus, fr. rapere to seize and carry off, to snatch or hurry away; perhaps akin to Gr. ἀρπάζειν: cf. F. rapide. Cf. Harpy, Ravish.]
1. Very swift or quick; moving with celerity; fast; as, a rapid stream; a rapid flight; a rapid motion.
Ascend my chariot; guide the rapid wheels. Milton.
2. Advancing with haste or speed; speedy in progression; in quick sequence; as, rapid growth; rapid improvement; rapid recurrence; rapid succession.
3. Quick in execution; as, a rapid penman.
Rap′id, n. [Cf. F. rapide. See Rapid, a.] 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.
Row, brothers, row, the stream runs fast, The rapids are near, and the daylight's past. Moore.