Hy-pŏt'e-nūse or Hy-pōt'e-nūse, n.

noun

n. [Fr. hypoténuse, Gr. ὑποτείνουσα, subtending (sc. γραμμή), from ὑποτείνειν, to stretch under, subtend; from ὑπό, under, and τείνειν, to stretch.] (Geom.) The subtense, or longest side of a right-angled triangle, or the line that subtends the right angle. [Written also hypothenuse.]

a b, hypotenuse.

A right triangle has the letters a and b marking its sides, with the hypotenuse identified in the caption. — *a b*, hypotenuse.