Source : Webster's Revised Unabridged Dictionary (1913)

Melaena \Me*l[ae]"na\, n. [NL., fr. Gr. me`las, m., me`laina,
   f., black.] (Med.)
   A discharge from the bowels of black matter, consisting of
   altered blood.

Source : WordNet®

melaena
     n : abnormally dark tarry feces containing blood (usually from
         gastrointestinal bleeding) [syn: {melena}]