'conservationist' originates from English, specifically formed from the noun 'conservation' plus the agent suffix '-ist', where 'conservation' ultimately comes from Latin 'conservatio' (from 'conservare') meaning 'to preserve or keep safe.'

'conservare' (Latin) led to Old French forms such as 'conserver' and 'conservation', which entered Middle English as 'conservacioun'/'conservation' and later gave modern English 'conservation'; adding the agent suffix '-ist' produced 'conservationist'.

Initially rooted in the idea 'to preserve or keep safe' (applied to things/actions), the sense extended to denote a person whose role or advocacy is preserving (today typically applied to people protecting nature, resources, or heritage).