There is no definitive explanation of the roots of the village's name, but its '-by' ending implies a link to Viking rule during the period of the Danelaw. Also, groo is a Viking word for pit, which may well refer to the quarry situated next to the village. The Domesday entry lists the village as 'Grobi'. The "Concise Oxford Dictionary of English Place-names" also shows the names "Groubi" or "Groebi" in the 12th century. Furthermore, it suggests the name is from a "tarn" perhaps with the Old Scandinavian name "grōf"; and that the Old Norse "gróf" means "a torrent and a gully formed by it." The dictionary also says, "It is identical with [ Gothic language ] "gróba", [ Old High German ] "grouba" 'pit, hollow'."