The Collaborative International Dictionary
catheti
Cathetus \Cath"e*tus\, n.; pl. catheti. [L., fr. Gr. ? a
perpendicular line, fr. ? let down, fr. ?. See Catheter.]
(Geom.)
One line or radius falling perpendicularly on another; as,
the catheti of a right-angled triangle, that is, the two
sides that include the right angle.
--Barlow.
Wiktionary
catheti
n. (plural of cathetus English)