'ankylosaurian' originates from New Latin 'Ankylosauria' with the English adjectival suffix '-ian'; ultimately from Greek 'ankylos' (ἀγκύλος) meaning 'bent, hooked, fused' and 'sauros' (σαῦρος) meaning 'lizard'.

'ankylosaurian' developed from the taxonomic name 'Ankylosauria' (coined in modern scientific Latin/Greek usage in the 19th century) and was adapted into English as the adjective/noun form 'ankylosaurian'.

Initially, the Greek roots described a 'fused' or 'bent' lizard (referring to fused armor/plates); over time the term came to denote members of the armored-dinosaur group Ankylosauria and things relating to them.