/ Dictionary / Index M Mount Wilson Observatory: Meaning and Definition of Find definitions for: Mount" Wil'son Observ'atory Pronunciation: [key] an astronomical observatory on Mount Wilson, near Los Angeles, California, having a 100-in. (254-cm) reflecting telescope. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Mount Washington Mounty Related Content Daily Word Quiz: abominable Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language