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

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

Initially, it meant 'to place under or in place of,' and over time it evolved into its current meaning of 'the ability to be replaced.'