quag I. \ˈkwag, ˈkwaa(ə)g, ˈkwäg, ˈkwaig\noun (-s) Etymology: origin unknown : marsh, bog, quagmire < the feet of the horse that slopped through sandy quags — Elizabeth M. Roberts > II. intransitive verb (quagged ; quagged ; quagging ; quags) Etymology: probably imitative archaic: quake, quiver, shake