a. [ L. rapidus, fr. rapere to seize and carry off, to snatch or hurry away; perhaps akin to Gr. 'arpa`zein: cf. F. rapide. Cf. Harpy, Ravish. ] [ 1913 Webster ]

1. Very swift or quick; moving with celerity; fast; as, a rapid stream; a rapid flight; a rapid motion. [ 1913 Webster ]

Ascend my chariot; guide the rapid wheels. Milton. [ 1913 Webster ]

2. Advancing with haste or speed; speedy in progression; in quick sequence; as, rapid growth; rapid improvement; rapid recurrence; rapid succession. [ 1913 Webster ]

3. Quick in execution; as, a rapid penman. [ 1913 Webster ]

a. Occurring in rapid succession like the shots fired from a machine gun. See also machine-gun. [ PJC ]

. (Ordnance) A mount permitting easy and quick elevation or depression and training of the gun, and fitted with a device for taking up the recoil. [ Webster 1913 Suppl. ]

{ }, a. (a) (Gun.) Firing shots in rapid succession. (b) (Ordnance) Capable of being fired rapidly; -- applied to single-barreled guns of greater caliber than small arms, mounted so as to be quickly trained and elevated, with a quick-acting breech mechanism operated by a single motion of a crank or lever (abbr. R. F.); specif.: (1) In the United States navy, designating such a gun using fixed ammunition or metallic cartridge cases; -- distinguished from breech-loading (abbr. B. L.), applied to all guns loading with the charge in bags, and formerly from quick-fire. Rapid-fire guns in the navy also sometimes include automatic or semiautomatic rapid-fire guns; the former being automatic guns of not less than one inch caliber, firing a shell of not less than one pound weight, the explosion of each cartridge operating the mechanism for ejecting the empty shell, loading, and firing the next shot, the latter being guns that require one operation of the hand at each discharge, to load the gun. (2) In the United States army, designating such a gun, whether using fixed or separate ammunition, designed chiefly for use in coast batteries against torpedo vessels and the lightly armored batteries or other war vessels and for the protection of defensive mine fields; -- not distinguished from quick-fire. (3) In Great Britain and Europe used, rarely, as synonymous with quick-fire. [ Webster 1913 Suppl. ]

n. [ L. rapiditas: cf. F. rapidité. ] The quality or state of being rapid; swiftness; celerity; velocity; as, the rapidity of a current; rapidity of speech; rapidity of growth or improvement. [ 1913 Webster ]

Syn. -- Rapidness; haste; speed; celerity; velocity; swiftness; fleetness; quickness; agility. [ 1913 Webster ]

adv. In a rapid manner. [ 1913 Webster ]

n. Quality of being rapid; rapidity. [ 1913 Webster ]

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; sometimes called whitewater; -- usually used in the plural; as, the Lachine rapids in the St. Lawrence. For boaters on the river, it is a place that can be hazardous, with danger of capsizing or crashing into large rocks. [ 1913 Webster +PJC ]

Row, brothers, row, the stream runs fast,
The rapids are near, and the daylight's past. Moore. [ 1913 Webster ]