rein

American  

[reyn] / reɪn /

noun

1. Often a leather strap, fastened to each end of the bit of a bridle, by which the rider or driver controls a horse or other animal by pulling so as to exert pressure on the bit.

2. any of certain other straps or thongs forming part of a harness, as a checkrein.

3. any means of curbing, controlling, or directing; check; restraint.

4. reins, the controlling or directing power.

   the reins of government.

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verb (used with object)

1. to check or guide (a horse or other animal) by exerting pressure on a bridle bit by means of the reins.

2. to curb; restrain; control.

   Synonyms:

   limit, bridle, check

verb (used without object)

1. to obey the reins.

   a horse that reins well.

2. to rein a horse or other animal.

idioms

1. give rein to, to give complete freedom to; indulge freely: Also give free rein to, give full rein to.

   to give rein to one's imagination.

2. draw rein, to curtail one's speed or progress; halt.

   The rider saw the snake and drew rein sharply.

rein British  

/ reɪn /

noun

1. (often plural) one of a pair of long straps, usually connected together and made of leather, used to control a horse, running from the side of the bit or the headstall to the hand of the rider, driver, or trainer

2. a similar device used to control a very young child

3. any form or means of control

   to take up the reins of government

4. the direction in which a rider turns (in phrases such as on a left ( or right ) rein , change the rein )

5. something that restrains, controls, or guides

6. to allow considerable freedom; remove restraints

7. to control carefully; limit

   we have to keep a tight rein on expenditure

8. with the reins held loosely so that the horse is relatively unconstrained

9. to take up the reins so that the distance between hand and bit is lessened, in order that the horse may be more collected

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verb

1. (tr) to check, restrain, hold back, or halt with or as if with reins

2. to control or guide (a horse) with a rein or reins

   they reined left

rein More Idioms  

1. see draw in the reins; free hand (rein) tight rein on.

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Other Word Forms

• reinless adjective
• unreined adjective

Etymology

Origin of rein

1300–50; (noun) Middle English rene, reine, raine < Old French re ( s ) ne < Vulgar Latin *retina, noun derivative of Latin retinēre to hold back, retain; (v.) Middle English rainen, reinen, derivative of the noun

Explanation

Rein is both a noun and a verb for guiding and restraining. You can use the long strap, or rein, on a horse to control its speed and direction, and you can rein in your own tongue by closing your mouth. Rein rhymes with rain but the two words describe very different things. Rain comes down all over the place, uncontrolled, while a rein holds things in place or controls what comes out. As a noun, rein is often used as a plural word "reins" when talking about actual leather restraints used in horse riding, but a rein also is something non-physical like when you put a rein on spending by shopping less.

Example Sentences

But there has also been talk of cutbacks, with many parties promising to reduce the number of "quangos" and rein in the size of the public sector.

From BBC • Apr. 23, 2026

It’s tempting to hang back, especially as companies rein in travel spending.

From The Wall Street Journal • Apr. 23, 2026

“When things started getting too crazy, I’d say, ‘Let’s rein it in.’”

From Los Angeles Times • Apr. 20, 2026

It also, though, showed a simple possible way to rein in the president’s ability to overreach in his war-making power.

From Slate • Apr. 15, 2026

They drew rein before the city gates, and looked up to see Dany on the wall above them.

From "A Clash of Kings" by George R.R. Martin

Related Words

• curb
• repress
• restrict
• suppress