topknot pigeon noun2 •A large pigeon, Lopholaimus antarcticus, native to eastern Australia. •(informal) A medium-sized pigeon, Ocyphaps lophotes, of Australia, having a pointed crest.A top-knot pigeon (Crested Pigeon), safe in its tangle of mimosa, breathes its little call of warning: `F'uff!' — 1934 formstopknot pigeons