/ Dictionary / Index T thermoplastic: Meaning and Definition of Find definitions for: ther•mo•plas•tic Pronunciation: (thûr"mu-plas'tik), [key] — adj. soft and pliable when heated, as some plastics, without any change of the inherent properties. —n. a plastic of this type. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: thermoplastic (Thesaurus) thermopile Thermopylae Related Content Daily Word Quiz: blithesome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language