/ Dictionary / Index T thermal barrier: Meaning and Definition of Find definitions for: ther'mal bar'rier Pronunciation: [key] — Aeron., Rocketry. Aeron.,Rocketry. the high temperatures produced by the friction between a supersonic object and the earth's atmosphere that limit the speed of an airplane or rocket. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thermal analysis thermal conductivity Related Content Daily Word Quiz: hale Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language