In planetary geology, an arcus (pl. arcũs) is an arc-shaped type of landform. [1] [2] Arcus is the Latin word for arc. [2]
As of 2022 the only named arcus are Hotei Arcus on Saturn's moon Titan [3] and Kaʼan Arcus on the primitive trans-Neptunian object 486958 Arrokoth. [4]