Columba

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A constellation in the Southern Hemisphere near Caelum and Puppis.
• Irish missionary who established a monastery on the island of Iona and subsequently Christianized northern Scotland.

from The Century Dictionary.

• noun Same as columbo.
• noun A genus of pigeons, formerly coextensive with the order Columbæ, now restricted to species typical of the family Columbidæ and subfamily Columbinæ, such as the domestic pigeon or rock-dove (C. livia), the stock-dove (C. ænas), the ring-dove (C. palumbus), and several others of both hemispheres.
• noun In conchology, a genus of bivalve mollusks.
• noun [l. c] [ML.] In the medieval church, the name given to the vessel in which the sacrament was kept, when, as was often the case, it was made in the shape of a dove.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Med.) See calumba.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• proper noun St. Columba of Iona (Old Irish Columb Cille, meaning "Dove of the church"); one of the Gaelic missionary monks who reintroduced Christianity to Scotland during the Dark Ages.
• proper noun Any of three other Christian saints who bore the name Columba.
• proper noun astronomy A small winter constellation of the northern sky, said to resemble a dove. It was introduced by Augustin Royer in 1679, as a split from the constellation Canis Major.
• proper noun A taxonomic genus within the family Columbidae — doves and pigeons.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun type genus of the Columbidae: typical pigeons
• noun a constellation in the southern hemisphere near Puppis and Caelum