'substitute' originates from Latin, specifically the word 'substituere,' where 'sub-' meant 'under' and 'statuere' meant 'to set or place.'

'substituere' transformed into the Old French word 'substituer,' and eventually became the modern English word 'substitute' through Middle English.

Initially, it meant 'to set or place under,' but over time it evolved into its current meaning of 'to replace or act in place of another.'