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

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