Who coined the name "tensor" and why? What does the word "tensor" really mean, not the mathematical definition?

$\begingroup$ Is this question appropriate for MO? The reasin I'm asking is that it does not address the mathematical term. $\endgroup$– Martin BrandenburgOct 1, 2011 at 11:08
2 Answers
I think the OP referes to the modern meaning of the word, in which case, according to that website, it first appeared in german physicist Woldemar Voigt's paper Die fundamentalen physikalischen Eigenschaften der Krystalle in elementarer Darstellung published in 1898. (I do not have access to this paper, but probably this deals with deformation tensors in crystals).

3$\begingroup$ This is the right answer. Voigt used the word tensor to describe stress and strain (i.e., things that stretched). In mechanics there is the stress tensor, strain tensor, and elasticity tensor. More precisely, it seems that what interested Voigt were special cases of symmetric tensors. See en.wikipedia.org/wiki/Woldemar_Voigt and en.wikipedia.org/wiki/Voigt_notation. $\endgroup$– KConradSep 18, 2011 at 20:09
A tensor muscle is a muscle that stretches some part of the body, e.g. the tensor veli palatini or tensor tympani. The word ultimately derives from the Latin tendere meaning "to stretch", see Douglas Harper's etymonline.
Hamilton first introduced the term to mathematics; see its entry in "Earliest Known Uses of Some of the Words of Mathematics".

2$\begingroup$ Hamilton's usage has been abandoned, however, and the word means something entirely different now. $\endgroup$ Sep 19, 2011 at 5:48