Rein \Rein\, v. t. [imp. & p. p. Reined (r?nd); p. pr. & vb. n. Reining.]

1. To govern or direct with the reins; as, to rein a horse one way or another.

He mounts and reins his horse. --Chapman.

2. To restrain; to control; to check.

Being once chafed, he can not Be reined again to temperance. --Shak.

To rein in or rein up, to check the speed of, or cause to stop, by drawing the reins.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Rein \Rein\, v. i. To be guided by reins. [R.]

--Shak.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Rein \Rein\ (r?n), n. [F. r[^e]ne, fr. (assumed) LL. retina, fr. L. retinere to hold back. See Retain.]

1. The strap of a bridle, fastened to the curb or snaffle on each side, by which the rider or driver governs the horse.

This knight laid hold upon his reyne. --Chaucer.

2. Hence, an instrument or means of curbing, restraining, or governing; government; restraint. ``Let their eyes rove without rein.'' --Milton.

To give rein, To give the rein to, to give license to; to leave withouut restrain.

To take the reins, to take the guidance or government; to assume control.

Source: Webster's Revised Unabridged Dictionary (1913)