/kath"i teuhs, keuh thee"teuhs/ , n. , pl. catheti /-tuy', -tuy/ .
(in an Ionic capital) the vertical guideline through the eye of a volute, from which the form of the volute is determined.
[ 1565-75; káthetos perpendicular, equiv. to kathe- (see CATHETER) + -tos adj. suffix ]