Căth'e-tĭs, n.

n.; pl. CĂTH'E-TĪ. [Lat. cathetus, Gr. κάθετος, f., (sc. γραμμή), a perpendicular line, from κάθετος, let down, of καθίημι, to send down. See supra.] (Geom.) A 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. [Obs.] Barlow.