/ Dictionary / Index M Mylar: Meaning and Definition of Find definitions for: My•lar Pronunciation: (mī'lär), [key] — Trademark. Trademark. a brand of strong, thin polyester film used in photography, recording tapes, and insulation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mylar (Thesaurus) My Lai Mylitta Related Content Daily Word Quiz: vernacular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language