/ Dictionary / Index P Plexiglas: Meaning and Definition of Find definitions for: Plex•i•glas Pronunciation: (plek'si-glas", -gläs"), [key] — Trademark. Trademark. a brand name for a thermoplastic polymer of methyl methacrylate that is light in weight, resistant to weathering, capable of being bent when hot but returning to its original shape when reheated, used for signs Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: plexiglas (Thesaurus) plexiform pleximeter Related Content Daily Word Quiz: mamba Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language