'ammocoetid' originates from Greek, specifically the word 'ammokoitēs,' where 'ammo-' meant 'sand' and 'koitēs' meant 'bed.'

'ammokoitēs' transformed into the scientific term 'ammocoetid' to describe the larval stage of lampreys.

Initially, it referred to 'sand bed,' but over time it evolved into its current meaning of 'larval stage of lampreys.'