n. 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. ; ; ;n. 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.n. In astronomy See Cygnus, 2.n. See def. 1.To swear: used in the phrase I swan, an expression of emphasis. Also swon.