'royalism' originates from French, specifically the word 'royalisme', where 'royal' meant 'kingly' and the suffix '-ism' meant 'doctrine, practice, or movement'.

'royalism' developed from the English adjective 'royal' (from Old French 'roial'/'royal'), which in turn comes from Latin 'regalis' meaning 'of a king'; the noun form with the suffix '-ism' was formed in English to denote a political doctrine or movement.

Initially, 'royal' meant 'kingly' or 'relating to a king'; over time the addition of '-ism' produced 'royalism', which came to mean 'the doctrine or practice of supporting monarchy'.