'clericalist' originates from English, specifically formed from the adjective 'clerical' plus the agentive suffix '-ist'; 'clerical' in turn originates from Medieval Latin 'clericalis', ultimately from Late Latin 'clericus' and Greek 'klerikos', where 'kleros' meant 'lot' or 'inheritance'.

'clericalist' changed from the modern English adjective 'clerical' (from Middle English and Old French forms such as 'cleric/clerc') with the addition of the English agentive suffix '-ist', developing from Late Latin 'clericus' and Greek 'klerikos' into the present English form 'clericalist'.

Initially related words denoted members of the clergy or those allotted by 'kleros' (a 'lot' or group); over time meanings shifted toward describing the institutional role and influence of clergy, and 'clericalist' came to mean a person who favors such clerical influence.