/ Dictionary / Index A apneustic: Meaning and Definition of Find definitions for: ap•neus•tic Pronunciation: (ap-n'stik, -ny'-), [key] — adj. Entomol. having no open spiracles, as the tracheal systems of certain aquatic insect larvae. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. apnea Apo Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language