'lancelet' originates from Modern Latin, specifically the word 'lanceolatus,' where 'lancea' meant 'lance' and the diminutive suffix '-let' means 'small.'

'lancelet' changed from the Modern Latin word 'lanceolatus' and eventually became the modern English word 'lancelet.'

Initially, it meant 'small lance,' referring to the shape of the animal, but over time it evolved into its current meaning of 'a small, primitive marine chordate.'