Lewis Short
sermōcĭnātrix (noun F) : sermocinator
* That converses, adapted to conversation; in rhet. lang., as a part of rhetoric, a transl. of the Platonic προσομιλητική, Quint. 3, 4, 10.—In gen.: immodica,i. e. a prattler, babbler,App. M. 9, p. 224, 31.
Charlton T. Lewis, Charles Short, A Latin Dictionary