'archaeoceti' originates from New Latin, specifically the word 'Archaeoceti', where the prefix 'archaeo-' comes from Greek 'archaios' meaning 'ancient' and the element 'ceti' (from Latin 'cetus', from Greek 'kētos') meant 'whale'.

'archaeoceti' was formed in scientific New Latin from Greek roots: Greek 'archaios' + Greek 'kētos' (rendered in Latin as 'cetus'), and was adopted as the modern taxonomic name 'Archaeoceti' in paleontology and zoology.

Initially the roots meant 'ancient' + 'whale', and this original literal meaning has been retained in modern usage to denote the group of 'ancient whales'.