'disestablishmentarianism' originates from English, specifically built from the elements 'dis-' + 'establishment' + '-arian' + '-ism', where 'dis-' meant 'apart, away', 'establish' (from Old French 'establir' / Latin 'stabilire') meant 'to set up, make firm', '-arian' meant 'pertaining to or advocating', and '-ism' meant 'belief, doctrine'.

'establish' came into English via Old French 'establir' (from Latin 'stabilire'/'stabilis'); 'establishment' developed to mean an established institution (especially an official church). In the 19th century the political term 'disestablishment' arose to denote removal of a church's official status; adding '-arian' produced 'disestablishmentarian' (one who advocates disestablishment), and '-ism' formed 'disestablishmentarianism' as the doctrine or movement.

Initially, components related to 'setting up' and 'removal' described concrete acts (to establish or to remove official status); over time the compound 'disestablishmentarianism' came to denote the broader political doctrine or movement favoring removal of a state church, a meaning that has remained stable in modern usage.