'ascidiozoa' originates from New Latin, ultimately from Greek, specifically from the Greek 'askidion' (diminutive of 'askis') meaning 'small bag' and Greek 'zoon' meaning 'animal'.

'ascidiozoa' developed from the genus name 'Ascidia' (borrowed into New Latin from Greek) combined with the suffix '-zoa' used for animal groups; it was used in older zoological literature and persisted as a scientific term in English as 'ascidiozoa'.

Initially it conveyed the image of 'small-bag animals' (referring to the bag-like body of these organisms); over time it came to be used chiefly as a taxonomic name for sea squirts.