\Ul*tro"ne*ous\, a. [L. ultroneus, from ultro to the
further side, on his part, of one's own accord. See
{Ultra-}.]
Spontaneous; voluntary. [Obs.] --Jer. Taylor. --
{Ul*tro"ne*ous*ly}, adv. [Obs.] -- {Ul*tro"ne*ous*ness}, n.
[Obs.]