/tedh"euhr/ , 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.
4. to fasten or confine with or as if with a tether.
[ 1350-1400; ME (n.); cf. ON tjothr, D tuier ]