/ Dictionary / Index B basion: Meaning and Definition of Find definitions for: ba•si•on Pronunciation: (bā'sē-on", -zē-), [key] — n. Craniom. the midpoint of the anterior margin of the foramen magnum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. basin range basipetal Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language