The Collaborative International Dictionary
Idiopathical
Idiopathic \Id`i*o*path"ic\, Idiopathical \Id`i*o*path"ic*al\, a. [Cf. F. idiopathique.] (Med.) Pertaining to idiopathy; characterizing a disease arising primarily, and not in consequence of some other disease or injury; -- opposed to symptomatic, sympathetic, and traumatic. -- Id`i*o*path"ic*al*ly, adv.
Wiktionary
idiopathical
a. (alternative form of idiopathic English)