'ankylosaur' originates from New Latin and Greek, specifically the Greek elements 'ankylos' meaning 'fused, bent' and 'sauros' meaning 'lizard'.

'ankylosaur' developed from the genus name 'Ankylosaurus' (coined in New Latin in the 19th century from Greek roots) and later came into general English usage as 'ankylosaur' to refer to members of the group Ankylosauria.

Initially formed from roots meaning 'fused lizard,' the term evolved to denote the specific group of heavily armored, club-tailed dinosaurs rather than a literal description of a 'fused lizard.'