n. & v.
n. (in sing. or pl.) 1 a long narrow strap with each end attached to the bit, used to guide or check a horse etc. in riding or driving. 2 a similar device used to restrain a young child. 3 a means of control.
v.tr. 1 check or manage with reins. 2 (foll. by up, back) pull up or back with reins. 3 (foll. by in) hold in as with reins; restrain. 4 govern, restrain, control. draw rein 1 stop one's horse. 2 pull up. 3 abandon an effort. give free rein to remove constraints from; allow full scope to. keep a tight rein on allow little freedom to. reinless adj.
[ ME f. OF rene, reigne, earlier resne, ult. f. L retinere RETAIN ]