1. to make Catholic in character, doctrine, or practice
Usage: chiefly British spelling; American English typically uses 'catholicize'; often used in historical or religious contexts
2. to convert to Catholicism
Usage: transitive use; less common than the first sense

Examples

• The missionary sought to catholicise the indigenous population.
• Efforts to catholicise the region met with resistance from Protestant communities.
• The reforms aimed to catholicise certain practices within the church.
• During the Counter-Reformation, many territories were catholicised.
• The institution gradually catholicised its traditions over several decades.