- Orthopnoea Or`thop*n[oe]"a, Orthopny Or*thop"ny, n. [L. orthopnoea, Gr. ?; 'orqo`sstraight, right + pnei^n to breathe: cf. F. orthopn['e]e.] (Med.) Specifically, a morbid condition in which respiration can be performed only in an erect posture; by extension, any difficulty of breathing. [1913 Webster]
The Collaborative International Dictionary of English. 2000.