|Origin:||rene, from Latin retinere; RETAIN|
1DSH [countable usually plural]
a long narrow band of leather that is fastened around a horse's head in order to control it [↪ bridle]
to allow an emotion or feeling to be expressed freely:
He gave free rein to his imagination.
to give someone complete freedom to do a job in whatever way they choose
to control something strictly:
The finance director keeps a tight rein on spending.
to take or give someone control over an organization or country:
Owens will officially take over the reins in a few weeks.