Tensor \Ten"sor\, n. [NL. See Tension.]

1. (Anat.) A muscle that stretches a part, or renders it tense.

2. (Geom.) The ratio of one vector to another in length, no regard being had to the direction of the two vectors; -- so called because considered as a stretching factor in changing one vector into another. See Versor.

Source: Webster's Revised Unabridged Dictionary (1913)