tight rein on, a

a tight rein on (someone or something)

Strict control or dominance over someone or something. Ever since George nearly lost his life savings in a drunken poker match, his husband has had a tight rein on him. We try to keep a tight rein on our expenditures, but that's not always possible. The country's government has maintained a tight rein over its people since coming to power.
See also: on, rein, tight
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

tight rein on, a

Strict control over, as in We told them to keep a tight rein on spending for the next year. This expression alludes to the narrow strap (rein) attached to a bit and used to control a horse's movements. Rein has been used to refer to any kind of restraint since the first half of the 1400s.
See also: rein, tight
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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