'anapsida' originates from New Latin, specifically the word 'Anapsida,' where 'an-' meant 'without' and 'apsis' meant 'arch' or 'loop,' referring to the lack of temporal openings in the skull.

'anapsida' was coined in the late 19th century in scientific classification to describe reptiles with skulls lacking temporal fenestrae, and it has remained in use in paleontology and zoology.

Initially, it meant 'reptiles without temporal skull openings,' and this meaning has remained consistent in modern scientific usage.