Wernicke's aphasia

...occurs due to damage to the left frontal lobe.
[Wernicke's aphasia (receptive aphasia)]
Speech is fluent and there is no agrammatism, but there are many grapheme paraphasias and word paraphasias. Speech that is fluent but has many grapheme paraphasias, word paraphasias, and neologisms and is difficult to understand is called jargon.

*Some of the terminology explanations that refer to "Wernicke's aphasia" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…左前頭葉の損傷で起こる。
［ウェルニッケ失語(感覚性失語)］
　話し言葉の表出は流暢で，失文法もないが，字性錯語や語性錯語が多い。このように流暢ではあるが字性錯語や語性錯語，新造語が多くて理解できない話し方をジャーゴンjargonと呼ぶ。…

※「ウェルニッケ失語」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報