The Collaborative International Dictionary of English v.0.48:
Idiopathy \Id`i*op"a*thy\, n.; pl. Idiopathies. [Gr. ?;
'i`dios proper, peculiar + ?, ?, to suffer: cf. F.
1. A peculiar, or individual, characteristic or affection.
All men are so full of their own fancies and
idiopathies, that they scarce have the civility to
interchange any words with a stranger. --Dr. H.
2. (Med.) A morbid state or condition not preceded or
occasioned by any other disease; a primary disease.