Cygnus

[sig-nuh s] /ˈsɪg nəs/
noun, genitive Cygni
[sig-nahy] /ˈsɪg naɪ/ (Show IPA).
Astronomy
1.
the Swan, a northern constellation southwest of Draco, containing the bright star Deneb.
Origin
< Latin: swan; see cygnet
British Dictionary definitions for Cygnus

Cygnus

/ˈsɪɡnəs/
noun (Latin genitive) Cygni (ˈsɪɡnaɪ)
1.
a constellation in the N hemisphere lying between Pegasus and Draco in the Milky Way. The constellation contains the Cygnus Loop supernova remnant, the intense radio galaxy Cygnus A, and the intense galactic X-ray source Cygnus X–1, which is probably a black hole
Word Origin
Latin: swan; see cygnet
Cygnus in Science
Cygnus
  (sĭg'nəs)   
A constellation in the Northern Hemisphere near Cepheus and Lyra. Cygnus (the Swan, or the Northern Cross) contains the bright star Deneb.