ultraradical

adj

1. Extremely radical, especially in politics.

   “An ultraradical Wahhabi fringe group was headed by Ayub Omarov (aka Ayub Astrakhansky), a Dagestani Avar from the Tsumadinskii raion. He resided in Astrakhan, and organized his ultraradical group among the Dagestani diaspora in that area.”

   “The Bolsheviks (the name derives from the Russian for big, or majority) were the ultra-radical faction of the Russian Social Democratic Labor Party and the direct ancestor of the Communist Party of the Soviet Union.”

noun

1. A root of the polynomial x⁵ + x + a, where a is a complex number.
2. An extreme political radical.