/ Dictionary / Index M mailbox: Meaning and Definition of Find definitions for: mail•box Pronunciation: (māl'boks"), [key] — n. a public box in which mail is placed for pickup and delivery by the post office. a private box, as at a home, into which mail is delivered by the mail carrier. a file for storing electronic mail. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mailbox (Thesaurus) mail bomb mail car Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language