tensor

Etymology

Borrowed from New Latin tensor (“that which stretches”), equivalent to tense + -or. Anatomical sense from 1704. Introduced in the 1840s by William Rowan Hamilton as an algebraic quantity unrelated to the modern notion of tensor. The contemporary mathematical meaning was introduced (as German Tensor) by Woldemar Voigt (1898) and adopted in English from 1915 (in the context of general relativity), obscuring the earlier Hamiltonian sense. The mathematical object is so named because an early application of tensors was the study of materials stretching under tension. (See, for example, Cauchy stress tensor on Wikipedia.Wikipedia)

noun

1. (anatomy) A muscle that tightens or stretches a part, or renders it tense.
2. (mathematics, linear algebra, physics) A mathematical object that describes linear relations on scalars, vectors, matrices and other algebraic objects, and is represented as a multidimensional array.
   The tensor αᵢⱼ should really be called a “tensor of second rank,” because it has two indexes. A vector—with one index—is a tensor of the first rank, and a scalar—with no index—is a tensor of zero rank. 1963, Richard Feynman, “Chapter 31, Tensors”, in The Feynman Lectures on Physics, volume II
3. (mathematics, obsolete) A norm operation on the quaternion algebra.

verb

1. To compute the tensor product of two tensors.