ul·tra·ist I. \-əə̇st\noun (-s) Etymology:ultra (I) + -ist : an adherent of ultraism : extremist, radical < the organ of the Argentine ultraists … roundly rejected Madrid's claim to chieftainship — Times Literary Supplement > II. adjective orul·tra·is·tic\| ̷ ̷ ̷ ̷|istik\ : of, relating to, or characteristic of ultraism