'additivity' originates from the Latin word 'additivus', where 'add-' meant 'toward' and 'dare' meant 'to give.'

'additivus' transformed into the French word 'additif', and eventually became the modern English word 'additive', from which 'additivity' is derived.

Initially, it meant 'the quality of being added,' but over time it evolved into its current meaning of 'the property of a system where the total effect is the sum of the individual effects.'