/ Dictionary / Index L lieutenant colonel: Meaning and Definition of Find definitions for: lieuten'ant colo'nel Pronunciation: [key] — U.S. Mil. U.S. Mil. a commissioned officer ranking next below a colonel and next above a major. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. lieutenant lieutenant commander Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language