tensor

A muscle that stretches or tightens a body part.

A set of quantities that obey certain transformation laws relating the bases in one generalized coordinate system to those of another and involving partial derivative sums. Vectors are simple tensors.

In anatomy, one of several muscles which tighten a part, or make it tense, or put it upon the stretch: differing from an extensor in not changing the relative position or direction of the axis of the part: opposed to laxator.

In mathematics, the modulus of a quaternion; the ratio in which it stretches the length of a vector.

In anatomy, noting certain muscles whose function is to render fasciæ or other structures tense.