/ Dictionary / Index A aplasia: Meaning and Definition of Find definitions for: a•pla•sia Pronunciation: (u-plā'zhu), [key] — n. Pathol. defective development or congenital absence of a limb, organ, or other body part. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: aplasia (Thesaurus) aplanospore aplastic anemia Related Content Daily Word Quiz: illegible Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language