Definitionen
1.AdjectiveExtreme; far beyond the norm; fanatical; uncompromising."an ultra reformer; ultra measures"
2.NounA political extremist, in particular:
An ultraleftist.
An ultranationalist.
An ultraroyalist.
3.NounAn ultraleftist.
4.NounAn ultranationalist.
5.NounAn ultraroyalist.
6.NounAn especially devoted football fan, typically organized and participating in choreographies (including pyrotechnics), often of outwardly intimidating demeanour, but distinguished from a violent hooligan (although overlap between both subcultures is possible)
7.NounAn ultramarathon.
8.NounAn ultra-prominent peak.
9.NounCode name used by British codebreakers during World War 2 for decrypted information gained from the enemy.