معنی کلمه :‌ tether

To confine, as an animal, with a long rope or chain, as for feeding within certain limits.

A long rope or chain by which an animal is fastened, as to a stake, so that it can range or feed only within certain limits.

(a) A simple visual organ found in many invertebrates, consisting of pigment cells covering a sensory nerve termination. (b) An eyelike spot of color.