- idiopathy (n.)
- 1640s, Modern Latin, from Greek idiopatheia, from comb. form of idios "one's own" (see idiom) + -patheia, comb. form of pathos "suffering, disease, feeling" (see pathos). Related: idiopathic.
- agnogenic
- "Of unknown origin or aetiology; cryptogenic; idiopathic", 1940s. From ancient Greek ἀγνώς unknown + -genic.