'mosasaur' originates from Latin, specifically the word 'Mosa' (referring to the Meuse River) and Greek 'sauros,' meaning 'lizard.'

'Mosa' combined with 'sauros' to form the term 'mosasaurus,' which eventually became the modern English word 'mosasaur.'

Initially, it meant 'lizard of the Meuse River,' but over time it evolved into its current meaning of 'a type of extinct marine reptile.'