Rock \Rock\, v. t. [imp. & p. p. Rocked;p. pr. & vb. n. Rocking.]

[AS. roccian; akin to Dan. rokke to move, to snake; cf. Icel. rukkja to pull, move, G. r["u]cken to move, push, pull.]

1. To cause to sway backward and forward, as a body resting on a support beneath; as, to rock a cradle or chair; to cause to vibrate; to cause to reel or totter.

A rising earthquake rocked the ground. --Dryden.

2. To move as in a cradle; hence, to put to sleep by rocking; to still; to quiet. ``Sleep rock thy brain.'' --Shak.

Note: Rock differs from shake, as denoting a slower, less violent, and more uniform motion, or larger movements. It differs from swing, which expresses a vibratory motion of something suspended.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Rocking \Rock"ing\, a. Having a swaying, rolling, or back-and-forth movement; used for rocking.

Rocking shaft. (Mach.) See Rock shaft.

Source: Webster's Revised Unabridged Dictionary (1913)