Gerontogeic: belonging to the old world: see neogeic.
Gibba: a rounded protuberance or prominence.
Gibbous: hump-backed; protuberant: said of a macula when it resembles a moon more than half full.
Gibbus: when the whole surface forms a hump or obtuse cone.
Gills: respiratory structures which function in water; distinguished as true or blood gills where contained blood conveys the absorbed oxygen from the gill to the tissues, and as tracheal gills when this conveyance is by contained tracheae.
Gilvus: = flavus; q.v.
Ginglymus: a hinge joint that permits flexion in one plane.
Gizzard: a pouch-like structure between the crop and chylific ventricle furnished with chitinous teeth or plates, in which the food is prepared for the digestive juices by grinding or merely sifting = cardia.
Glaber-rous: smooth; free from all vestiture.
Gland: a cellular sac which separates or secretes from the blood specific portions to produce characteristic products - e.g. wax, saliva, silk, etc.