ultras

noun

1. 1

   An ultraroyalist in France.

2. 2

   An extremist, especially an ultranationalist.

3. 3

   An especially devoted football fan, typically associated with the intimidating use of extremist slogans, pyrotechnics and sometimes hooligan violence.

4. 4

   An ultramarathon.

5. 5

   An ultra-prominent peak.

6. 6

   (usually capitalised) Code name used by British codebreakers during World War 2 for decrypted information gained from the enemy.