(1):
(n.) The constellation Cygnus.
(2):
(n.) Any one of numerous species of large aquatic birds belonging to Cygnus, Olor, and allied genera of the subfamily Cygninae. 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.
(3):
(n.) Fig.: An appellation for a sweet singer, or a poet noted for grace and melody; as Shakespeare is called the swan of Avon.