SAG, SAg, or sag may refer to: Land formations Sag (geology), or trough, a depressed, persistent, low area Sag pond, a body of water collected in the lowest parts of a depressionPeople Ivan Sag (1949–2013), American linguistPlaces Šag, a village near Osijek in Croatia Sâg, a commune located in Sălaj County, Romania Șag, a commune in Timiș County, Romania Sag Harbor, New York, a village in Suffolk County, New York, USA The Sag, a colloquialism for the Sagtikos State Parkway on Long Island, New YorkScience Short for Sagittarius, a zodiac sign SAg, short for superantigen SAG (gene), encodes the protein S-Arrestin in humans Sagitta (optics), a measure of lens surface shape Smoothened agonist, a small bioactive molecule Lens sag, distortion of astronomical lenses and mirrors Voltage sag or voltage dip, brief drop in voltage SAG or single amplified...