'amphioxidae' originates from Greek, specifically the word 'amphi' meaning 'both' and 'oxys' meaning 'sharp,' referring to the pointed ends of the lancelet's body.

'amphi' and 'oxys' combined to form the Greek word 'amphioxus,' which was later adapted into the scientific classification 'amphioxidae.'

Initially, it referred to the sharp, pointed nature of the organism, and this meaning has largely remained the same in modern usage.