'ascidiozooid' originates from New Latin and Greek: the combining form 'ascidio-' (from New Latin 'Ascidia', a genus of tunicates) and 'zooid' from Greek 'zooeidēs', where 'zoion' meant 'animal' and the element '-oeidēs' meant 'like' or 'resembling'.

'ascidiozooid' was formed in modern scientific English by combining the New Latin/root element 'ascidio-' (relating to ascidians) with the Greek-derived 'zooid' (meaning 'animal-like unit'), following conventional coinages in 19th–20th century zoological terminology.

Initially it referred specifically to 'a zooid of an ascidian colony', and over time the term has retained this specialized zoological meaning with little change.