Ultra-

Ultra- \Ul"tra-\, a.
   A prefix from the Latin ultra beyond (see {Ulterior}), having
   in composition the signification beyond, on the other side,
   chiefly when joined with words expressing relations of place;
   as, ultramarine, ultramontane, ultramundane, ultratropical,
   etc. In other relations it has the sense of excessively,
   exceedingly, beyond what is common, natural, right, or
   proper; as, ultraconservative; ultrademocratic,
   ultradespotic, ultraliberal, ultraradical, etc.
   [1913 Webster]
    

Ultra \Ul"tra\, a. [See {Ultra-}.]
   Going beyond others, or beyond due limit; extreme; fanatical;
   uncompromising; as, an ultra reformer; ultra measures.
   [1913 Webster]
    

Ultra \Ul"tra\, n.
   One who advocates extreme measures; an ultraist; an
   extremist; a radical. --Brougham.
   [1913 Webster]
    

41 Moby Thesaurus words for "ultra":
      Bolshevik, Jacobin, Wobbly, anarchist, anarcho-syndicalist,
      at the height, at the limit, extreme, extreme left-winger,
      extremist, fanatic, far out, furthest, greatest, kinky,
      left-wing extremist, lunatic fringe, mild radical, most, nihilist,
      outre, parlor Bolshevik, parlor pink, pink, pinko, rabid, radical,
      red, revolutional, revolutionary, revolutionist, sans-culotte,
      subversive, syndicalist, too much, ultra-ultra, ultraist, utmost,
      uttermost, way out, yippie