Definition -
(1) Talking too much as an illness.
(2) Talking too much in general.

Etymology -
The term derives from the Greek logos, word + rhein, to flow.

Oxford English Dictionary -
Its first citation is from 1902:
"Logorrhea refers to the excessive flow of words, a common symptom in cases of mania."
(Baldwin Dict. Philos. & Psychol. II. 30/1 )

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