What is "paraphasia"

n. (context medicine English) A symptom of aphasia in which the sufferer substitutes a spoken word different from the one intended.

Paraphasia is a type of language output error commonly associated with aphasia, and characterized by the production of unintended syllables, words, or phrases during the effort to speak. Paraphasic errors are most common in patients with fluent forms of aphasia, and comes in three forms: phonemic or literal, neologistic, and verbal. Paraphasias can affect metrical information, segmental information, number of syllables, or both. Some paraphasias preserve the meter without segmentation, and some do the opposite. However, most paraphasias affect both partially.

The term was apparently introduced in 1877 by the German-English physician Julius Althaus in his book on Diseases of the Nervous System, in a sentence reading, "In some cases there is a perfect chorea or delirium of words, which may be called paraphasia".