rein

Etymology 1

From Middle English rein, reyne, borrowed from Anglo-Norman reyne, resne, from Early Medieval Latin retina, ultimately from Classical Latin retineō (“hold back”), from re- + teneō (“keep, hold”). Compare modern French rêne. Displaced native Old English ġewealdleþer (literally “control leather”).

noun

1. A strap or rope attached to a bridle or bit, used to control a horse, animal or young child.
2. (figurative) An instrument or means of curbing, restraining, or governing.
   The government is attempting to keep a rein on rising prices.

verb

1. (transitive) To direct or stop a horse by using reins.
2. (transitive) To restrain; to control; to check.
   After an interval that he judged to have lasted twenty minutes, the bed began to shake with poorly reined sobs. 2001, Jonathan Franzen, The Corrections
3. (intransitive) To obey directions given with the reins.
   She worked each horse at a walk, trot, and then a canter. The horses reined well and executed stops quickly. 2011, Marie Claire Peck, Rocking Horse Ranch, page 40

Etymology 2

table From Anglo-Norman reines, Middle French reins, and their source, Latin rēnēs. Doublet of ren.

noun

1. (now rare, archaic, chiefly in plural) A kidney.
2. The inward impulses; the affections and passions, formerly supposed to be located in the area of the kidneys.