sea swallow

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

• noun Any of various terns, especially Sterna hirundo, which breeds in Arctic and subarctic regions.

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

• The common tern.
• The storm petrel.
• The gannet.
• (Her.) See Cornish chough, under Chough.

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

• noun UK The common tern.

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

• noun common tern of Eurasia and America having white black and grey plumage