Las′so, a thin, plaited rope of rawhide used for catching wild animals. One end is fastened to the saddle of the hunter, and the other, ending in a ring, forms a loose, sliding noose, which, after being whirled around in the right hand, is thrown over the object. In Mexico, where it is called la reata, and in the United States, where it is called a lariat, it often is made of plaited hair.