/ Dictionary / Index T thoracostomy: Meaning and Definition of Find definitions for: tho•ra•cos•to•my Pronunciation: (thôr"u-kos'tu-mē, thōr"-), [key] — pl. -mies. the construction of an artificial opening through the chest wall, usually for the drainage of fluid or the release of an abnormal accumulation of air. the opening so constructed. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thoracoplasty thoracotomy Related Content Daily Word Quiz: wizened Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language