'jawless' originates from the English word 'jaw' combined with the suffix '-less', where 'jaw' refers to the bony structure in the mouth and '-less' indicates absence.

'jaw' changed from the Old English word 'ceafl' and eventually became the modern English word 'jaw'.

Initially, 'jaw' referred to the bony structure in the mouth, and 'jawless' has consistently meant lacking this structure.