Lariat

Webster's Dictionary of the English Language

·vt To secure with a lariat fastened to a stake, as a horse or mule for grazing; also, to lasso or catch with a lariat.

II. Lariat ·noun A long, slender rope made of hemp or strips of hide, ·esp. one with a noose;

— used as a lasso for catching cattle, horses, ·etc., and for picketing a horse so that he can graze without wandering.