the world > the earth > structure of the earth > structural features > fold or dip > [adjective] > syncline
synclinal1833
synclinical1838
synclinorial1880
synclinorian1883
1883 A. WinchellWorld-life (1889) 331 Geosynclinals are in progress beneath the sea, which will never attain synclinorian crises unless some revolution provides supplies of sediments.