/ Dictionary / Index F foramen magnum: Meaning and Definition of Find definitions for: fora'men mag'num Pronunciation: (mag'num), [key] — Anat. Anat. the large opening in the base of the skull forming the passage from the cranial cavity to the spinal canal. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. foramen foraminate Related Content Daily Word Quiz: belligerent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language