Definitions
1.nounAn ultraroyalist in France.
2.nounAn extremist, especially an ultranationalist.
3.nounAn especially devoted football fan, typically associated with the intimidating use of extremist slogans, pyrotechnics and sometimes hooligan violence.
4.nounAn ultramarathon.
5.nounAn ultra-prominent peak.
6.noun(usually capitalised) Code name used by British codebreakers during World War 2 for decrypted information gained from the enemy.
7.adjectiveExtreme; far beyond the norm; fanatical; uncompromising."an ultra reformer; ultra measures"