'schemer' originates from the word 'scheme', which comes from the Greek word 'skhema', meaning 'form' or 'figure'.

'skhema' transformed into the Latin word 'schema', and eventually became the modern English word 'scheme', from which 'schemer' is derived.

Initially, it meant 'a form or figure', but over time it evolved into its current meaning of 'a person who makes secret plans'.