'pro-Remonstrant' originates from Latin and Dutch elements: the prefix 'pro-' (from Latin 'pro') meaning 'for', and 'Remonstrant' (from Dutch 'Remonstrant' referring to members of the Remonstrant movement), the latter ultimately tracing to Latin 'remonstrare' meaning 'to show or point out.'

'Remonstrant' entered English as a designation for followers of the Dutch Remonstrance of 1610 (Dutch 'Remonstranten'), itself deriving from French/Latin roots (Latin 'remonstrare' → Old French remonstrer → Dutch Remonstrant), and the compound 'pro-Remonstrant' was formed in English to mean 'in favor of the Remonstrants.'

Initially, forms of 'remonstrant' simply meant 'one who remonstrates' or 'one who protests'; over time, in a historical and religious context it came to denote specifically members of the Dutch Arminian movement, and 'pro-Remonstrant' came to mean 'supporting that movement.'