barn swallow

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

• noun A widely distributed bird (Hirundo rustica) that nests in barns and caves and has a deeply forked tail, a dark-blue back, and tan underparts.

from The Century Dictionary.

• noun The common swallow of the United States, Hirundo horreorum or H. erythrogastra: so called because it habitually breeds in barns.

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

• noun The most widespread species of swallow in the world; a distinctive passerine bird with blue upperparts, a long, deeply forked tail and curved, pointed wings, is found in Europe, Asia, Africa and the Americas.

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

• noun common swallow of North America and Europe that nests in barns etc.