from
The Collaborative International Dictionary of English v.0.48
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.
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This knight laid hold upon his reyne. --Chaucer.
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2. Hence, an instrument or means of curbing, restraining, or
governing; government; restraint. "Let their eyes rove
without rein." --Milton.
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{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.
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