rein

 
Pronunciation: /reɪn/

noun

(usually reins)
  • a long, narrow strap attached at one end to a horse’s bit, typically used in pairs to guide or check a horse in riding or driving.
  • British a pair of straps used to restrain a young child: some of the children wore leather baby reins
  • the power to direct and control: a new chairperson will soon take over the reins

verb

[with object and adverbial]
  • check or guide (a horse) by pulling on its reins: he reined in his horse and waited
  • keep under control; restrain: with an effort, she reined back her impatience the government had failed to rein in public spending

Phrases

draw rein

British stop one’s horse: he drew rein and waited for his friend to catch up

(a) free rein

freedom of action or expression: he was given free rein to work out his designs

keep a tight rein on

exercise strict control over: her only chance of survival was to keep a tight rein on her feelings

Origin:

Middle English: from Old French rene, based on Latin retinere 'retain'

The idiomatic phrase a free rein, which derives from the literal meaning of using reins to control a horse, is sometimes misinterpreted and written as a free reign. More than a third of the citations for the phrase in the Oxford English Corpus use reign instead of rein.