in pathology, "loss of ability to speak," especially as result of brain injury or disorder, 1867, from Modern Latin aphasia, from Greek aphasia "speechlessness," abstract noun from a- "without" (see a- (3)) + phasis "utterance," from phanai "to speak," related to phēmē "voice, report, rumor" from PIE root *bha- (2) "to speak, tell, say").
APHASIA is the term which has recently been given to the loss of the faculty of articulate language, the organs of phonation and of articulation, as well as the intelligence, being unimpaired. The pathology of this affection is at the present time the subject of much discussion in the scientific world; the French Academy devoted several of their séances during the year 1865 to its special elucidation, and the Medical Journals of France and of our own country have lately contained a good deal of original matter bearing upon this obscure feature in cerebral pathology. [Frederic Bateman, M.D., "Aphasia," London, 1868]
Middle English -ik, -ick, word-forming element making adjectives, "having to do with, having the nature of, being, made of, caused by, similar to," from French -ique and directly from Latin -icus or from cognate Greek -ikos "in the manner of; pertaining to." From PIE adjective suffix *-(i)ko, which also yielded Slavic -isku, adjectival suffix indicating origin, the source of the -sky (Russian -skii) in many surnames. In chemistry, indicating a higher valence than names in -ous (first in benzoic, 1791).
In Middle English and after often spelled -ick, -ike, -ique. Variant forms in -ick (critick, ethick) were common in early Modern English and survived in English dictionaries into early 19c. This spelling was supported by Johnson but opposed by Webster, who prevailed.
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Definitions of aphasic from WordNet
related to or affected by aphasia;
unable to speak because of a brain lesion;
someone affected by aphasia or inability to use or understand language;