'wormer' originates from English, specifically from the word 'worm' with the agent suffix '-er', where 'worm' meant 'parasitic worm' and '-er' meant 'one who or that which'.

'wormer' was formed in English by combining 'worm' and the suffix '-er', and has been used since the 19th century to refer to substances that expel worms.

Initially, it meant 'a person or thing that removes worms', but over time it evolved into its current meaning of 'a medicine or substance used to expel or destroy parasitic worms'.