0 a person who has extreme political or religious opinions, or opinions that are more extreme than others in the same political party, etc.: --
1 a running race that is longer than a marathon (= a race that is approximately 26 miles): --
ultra-cycling/ultra-running events
an ultra-short haircut
ultra-sensitive
ultra-modern architecture
ultra-expensive
ultramodern
ultraconservative
4 used with adjectives to mean 'extremely': --
The network uses ultra-fast fiber-optic cable.
These ultra-thin loudspeakers can be hidden as paintings on a wall.
Ultrarunners are comfortable with extremes, and today the race has become one of the preeminent ultras in the country.
He needs to compete and win a lot of normal ultras before he could be classified as the best ever in that arena.
From the central lower section of the north end the ultras fired flares and bellowed their anthem.
Banners for the Ultras of the Curva Nord (of Rome's Olympic stadium) were flying high.
As did the McCarthyites of the previous decade, the ultras argued vehemently that the real threat to the nation's security resided in communist subversion at home.
The ultras were mounting their own campaign to unseat the senator.