/ Dictionary / Index A alkaline earth: Meaning and Definition of Find definitions for: al'kaline earth' Pronunciation: [key] — Chem. Chem. any of the oxides of barium, radium, strontium, calcium, and, sometimes, magnesium. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. alkaline alkaline-earth metal Related Content Daily Word Quiz: exemplary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language