'additionist' originates from the English word 'addition,' combined with the suffix '-ist,' which denotes a person who practices or is concerned with something.

'addition' comes from the Latin word 'additio,' meaning 'a bringing to or adding.' The suffix '-ist' is derived from the Greek '-istes,' indicating a person associated with a particular action or doctrine.

Initially, it meant 'a person who adds,' but over time it evolved into its current meaning of 'a person who advocates for the addition of something.'