/ Dictionary / Index M midsagittal plane: Meaning and Definition of Find definitions for: mid•sag'it•tal plane' Pronunciation: (mid-saj'i-tl), [key] — Craniom. Craniom. a plane passing through the nasion when the skull is oriented in the Frankfurt horizontal. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mid-rise midsection Related Content Daily Word Quiz: pugilist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language