Lewis & Short

hypŏtēnūsa, ae, f., = ὑποτείνουσα, the hypothenuse, Hyg. de Limit. p. 176 Goes. Boëth. Art. Geom. p. 408, 20.
Hence, hy-pŏtēnūsālis, e, adj., of or belonging to the hypothenuse, Boëth. Art. Geom. p. 412, 5 al.