'sauropsidan' originates from New Latin, specifically the term 'Sauropsida', where Greek 'sauros' meant 'lizard' and Greek 'ōps/opsis' meant 'appearance' or 'face'. The English suffix '-an' was added to indicate a member or adjective form.

'Sauropsida' was coined in the 19th century in zoological classification from Greek roots; the form 'sauropsidan' developed by adding the English/Latin-derived suffix '-an' to denote an individual belonging to or relating to that group.

Initially built from roots meaning 'lizard appearance', the term evolved from a descriptive phrase to a formal taxonomic name and then to forms (like 'sauropsidan') meaning 'a member of' or 'relating to' that clade.