Pronunciation: (te&thslash;'ur),[key] —n. 1. a rope, chain, or the like, by which an animal is fastened to a fixed object so as to limit its range of movement.
2. the utmost length to which one can go in action; the utmost extent or limit of ability or resources.
3. at the end of one's tether, at the end of one's resources, patience, or strength.
—v.t. to fasten or confine with or as if with a tether.