The Collaborative International Dictionary of English v.0.48:

Columba \Co*lum"ba\, n. (Med.)
   See Calumba.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Columba
    n 1: a constellation in the southern hemisphere near Puppis and
         Caelum [syn: Columba, Dove]
    2: type genus of the Columbidae: typical pigeons [syn:
       Columba, genus Columba]