Source : Webster's Revised Unabridged Dictionary (1913)

Hemoptysis \He*mop"ty*sis\, n. [NL., fr. Gr. a"i^ma blood + ? to
   spit: cf. F. h['e]moptysie.] (Med.)
   The expectoration of blood, due usually to hemorrhage from
   the mucous membrane of the lungs.

Source : WordNet®

hemoptysis
     n : coughing up blood from the respiratory tract; usually
         indicates a severe infection of the bronchi or lungs
         [syn: {haemoptysis}]
     [also: {hemoptyses} (pl)]