/ Dictionary / Index M Mailgram: Meaning and Definition of Find definitions for: Mail•gram Pronunciation: (māl'gram"), [key] — Trademark. Trademark. a message transmitted electronically to the post office nearest the addressee and then delivered by regular mail. the service that sends such messages. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mail flag mail-in Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language