overtalkative

adjective

over·​talk·​a·​tive ˌō-vər-ˈtȯ-kə-tiv 

: abnormally or excessively talkative : tending to talk too much

overtalkative children

In a high mood the person may be overtalkative, overactive, spend excessively and be elated or extremely irritable.

—Patricia Casey

overtalkativeness noun

Manic episodes typically are characterized by hyperactivity, elation, overtalkativeness, tremendous energy, decreased need for sleep, and, usually but not always, poor judgment.

—National Institute of Mental Health

Word History

First Known Use

circa 1667, in the meaning defined above