One who capitalises; a person or agent that writes with capital letters or converts assets into investment capital.
From capitalise plus the agent suffix -r/-er. The term emerged in the 19th century in both typographic and economic contexts.
In the British spelling, a 'capitaliser' could be an overeager editor obsessively capitalizing Words That Shouldn't Be Capitalized—or a ruthless investor who exploits Every Opportunity for Profit!
Complete word intelligence in one call. Free tier — 50 lookups/day.