IDIOPATHY
Etymology
Noun
idiopathy (plural idiopathies)
Something idiopathic; a disease having no known cause.
Source: Wiktionary
Id`i*op"a*thy, n.; pl. Idiopathies. Etym: [Gr. idiopathie.]
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. More.
2. (Med.)
Definition: A morbid state or condition not preceded or occasioned by any
other disease; a primary disease.
Source: Webster’s Unabridged Dictionary 1913 Edition