1. Either of two long narrow straps attached to each end of the bit of a bridle and used by a rider or driver to control a horse or other animal: The left rein slipped out of the driver's hands. The rider pulled on the reins, and the horse began to slow down.
2. A means of restraining or checking: kept a tight rein on expenditures.
3. often reins A means of controlling or directing: the reins of government.
v. reined, rein·ing, reins
1. To check or hold back by the use of reins. Often used with in or up: reined in the horse.
2. To restrain or control. Often used with in: "a team of strong personalities who would test the limits of prudence unless kept firmly reined in" (Tim Zimmermann).
To control a horse, for example, with reins. Often used with in or up.
To stop a horse, for example, by pulling on the reins.
draw in the reins
1. To slow down or stop a horse or other animal by putting pressure on the reins.
2. To restrain or control.
give free/full rein to
To release from restraints; allow to go unchecked: gave free rein to her emotions.
[Middle English, from Old French resne, reine, from Vulgar Latin *retina, from Latin retinēre, to retain; see RETAIN.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.