Aphasia \A*pha"si*a\, Aphasy \Aph"a*sy\, n. [NL. aphasia, Gr. ?, fr. ? not spoken; 'a priv. + ? to speak: cf. F. aphasie.] (Med.) Loss of the power of speech, or of the appropriate use of words, the vocal organs remaining intact, and the intelligence being preserved. It is dependent on injury or disease of the brain.