/ Dictionary / Index C cubitus: Meaning and Definition of Find definitions for: cu•bi•tus Pronunciation: (ky'bi-tus), [key] — pl. -ti a longitudinal vein in the rear portion of the wing of an insect. the forearm. Now Rare.the ulna. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: cubitus (Thesaurus) cubital furrow cuboid Related Content Daily Word Quiz: reluctant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language