Word Study
orthopny
CIDE DICTIONARY
orthopny, n. [L. orthopnoea, Gr. ; 'orqo`sstraight, right + pnei^n to breathe: cf. F. orthopnée.].
Specifically, a morbid condition in which respiration can be performed only in an erect posture; by extension, any difficulty of breathing. [1913 Webster]
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