'ancylus' originates from Neo-Latin, specifically the word 'Ancylus,' which was used as a genus name in taxonomy, derived from Greek 'ankýlos' meaning 'crooked' or 'bent.'

'Ancylus' was adopted in scientific Latin in the 19th century as a genus name for certain freshwater limpets, and has remained in use in taxonomy.

Initially, it referred to the shape ('crooked, bent') but became the name for a genus of limpets due to their shell shape.