spontaliter
spontāliter, Adv. (spontalis), freiwillig, von selbst, Sidon. epist. 8, 9, 2. Anecd. Helv. 55, 18.
spontālĭter Sid. Ep. 8, 9 ; spontānĕē Hier. Ep. 52, 7, spontanément.
Id non modo non coactus, verum etiam Spontaliter facio.