rein

1 of 2

noun

ˈrān 

1

: a strap fastened to a bit by which a rider or driver controls an animal

—usually plural

2

a

: a restraining influence : check

kept a tight rein on the proceedings

b

: controlling or guiding power

—usually plural

the reins of government

3

: opportunity for unhampered activity or use

gave full rein to her imagination

Illustration of rein

• R rein 1

rein

2 of 2

verb

reined; reining; reins

transitive verb

1

: to control or direct with or as if with reins

2

: to check or stop by or as if by a pull at the reins

reined in her horse

couldn't rein his impatience

intransitive verb

1

: to stop or slow up one's horse or oneself by or as if by pulling the reins

2

archaic : to submit to the use of reins

Synonyms of rein

Noun

• helm
• chair

Verb

• contain
• regulate
• curb
• control
• keep
• restrain

Examples of rein in a Sentence

Noun

He has people working for him, but he has a tight rein on every part of the process.

after the president resigned, the vice president stepped in and took the reins of the company

Verb

try to rein in your spending, so you have some money left for saving

Recent Examples on the Web

Noun

Bilton, who seized the reins of the show as executive producer earlier this year, may not want to shake things up overmuch in a season debut. — Brian Steinberg, Variety, 14 Sep. 2026

At 50, Ternus is the same age as ​Cook when ⁠he took over the reins as CEO from co-founder Steve Jobs in 2011. — Greta Cross, USA Today, 9 Sep. 2026

Verb

The gathering in Scotland was convened to discuss how AI can benefit society, and comes at a pivotal moment for the technology as debate swirls around whether rapid advances will soon put it beyond the ability of humans to rein it in. — ABC News, 17 Sep. 2026

And as the budget deficit heads toward $2 trillion a year with no sign of lawmakers trying to rein it in, the market is getting skittish about continuing to lend to the federal government at such levels. — Jason Ma, Fortune, 6 Sep. 2026

Word History

Etymology

Noun

Middle English reine, from Anglo-French resne, reine, from Vulgar Latin *retina, from Latin retinēre to restrain — more at retain

First Known Use

Noun

13th century, in the meaning defined at sense 1

Verb

15th century, in the meaning defined at transitive sense 1

Phrases Containing rein

• bearing rein
• free rein
• keep a rein on
• neck-rein
• rein in

Rhymes for rein

• ane
• bane
• blain
• brain
• cane
• chaine
• cheyne
• deign
• drain
• fain
• fane
• feign

Kids Definition

rein

1 of 2 noun

ˈrān 

1

: a line or strap fastened to a bit on each side for controlling an animal (as a horse)

—usually used in plural

2

a

: an influence that slows, limits, or holds back

kept the child under a tight rein

b

: controlling or guiding power

—usually used in plural

seized the reins of government

3

: complete freedom : scope

gave full rein to her imagination

rein

2 of 2 verb

: to check, control, or stop by or as if by reins

reined in the horse

couldn't rein his impatience