biloquial

Probably coined by American novelist Charles Brockden Brown (1771-1810).

biloquial (not comparable)

1. (rare) Of, pertaining to, or possessing the ability to speak in two different voices, especially as a ventriloquist.
   • 1805, Charles Brockden Brown, chapter 5, in Memoirs of Carwin the Biloquist:

     Deception was often unnecessarily practised, and my biloquial faculty did not lie unemployed . . . . Standing one evening on the steps of the great altar, this devout friar expatiated on the miraculous evidences of his religion; and, in a moment of enthusiasm, appealed to San Lorenzo, whose martyrdom was displayed before us. No sooner was the appeal made than the saint, obsequious to the summons, whispered his responses from the shrine.

• biloquism
• biloquist
• biloquium

• Oxford English Dictionary, 2nd ed., 1989.