A radical is a person subscribing to a political ideology supporting massive, unmeasured, and rapid
change. Radicalism is contrasted with conservatism that advocate minimum
change, reactionary action advocating counter-
change, as well as progressivism advocating moderate/measured change.
A radical would want to chang, for example, a feudal system into a completely capitalist system, or a completely capitalist system into a
communist one. Another exaple of radicalism would be a person who wanted to
change an Islamic Theocracy into an Atheist state (see en.wikipedia.org/wiki/state_
atheism)!