/ Dictionary / Index F Fiberglas: Meaning and Definition of Find definitions for: Fi•ber•glas Pronunciation: (fī'bur-glas", -gläs"), [key] — Trademark. Trademark. a brand of fiberglass. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. fiberfill fiberglass Related Content Daily Word Quiz: feline Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language