extreme philosophy, belief, or action
WordReference Random House Unabridged Dictionary of American English © 2025
ul•tra•ism
(ul′trə iz′əm),USA pronunciation n.
ul′tra•ist, n., adj.
ul′tra•is′tic, adj.
- extremism.
- an extremist point of view or act.
- ultra- + -ism 1815–25
ul′tra•is′tic, adj.
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