swan

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

• noun Any of various large waterbirds of the genera Cygnus and Coscoroba of the family Anatidae, having webbed feet, a long slender neck, and usually white plumage.
• intransitive verb To travel around from place to place.
• intransitive verb To declare; swear. Used in the phrase I swan as an interjection.

from The Century Dictionary.

• To swear: used in the phrase I swan, an expression of emphasis. Also swon.
• noun A large lamellirostral palmiped bird, of the family Anatidæ and subfamily Cygninæ, with a long and flexible neck, naked lores, reticulate tarsi, and simple or slightly lobed hallux. ; ; ;
• noun In heraldry, a bearing representing a swan, usually with the wings raised as it carries them when swimming. It is therefore not necessary to say in the blazon “with wings indorsed.” See below.
• noun In astronomy See Cygnus, 2.
• noun See def. 1.

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

• noun (Zoöl.) Any one of numerous species of large aquatic birds belonging to Cygnus, Olor, and allied genera of the subfamily Cygninæ. They have a large and strong beak and a long neck, and are noted for their graceful movements when swimming. Most of the northern species are white. In literature the swan was fabled to sing a melodious song, especially at the time of its death.
• noun Fig.: An appellation for a sweet singer, or a poet noted for grace and melody.
• noun (Astron.) The constellation Cygnus.
• noun (Zoöl.) a bird of India (Cygnopsis cygnoides) resembling both the swan and the goose.
• noun a large size of shot used in fowling.

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

• verb US, slang To declare (chiefly in first-person present constructions).
• noun Any of various species of large, long-necked waterfowl, of genus Cygnus, most of which have white plumage.
• noun figuratively One whose grace etc. suggests a swan.
• verb UK (intransitive) To travel from place to place with no fixed itinerary or purpose.

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

• verb sweep majestically
• noun stately heavy-bodied aquatic bird with very long neck and usually white plumage as adult
• verb move about aimlessly or without any destination, often in search of food or employment
• verb to declare or affirm solemnly and formally as true