radicalism

In politics, a radical is someone who desires significant or extreme change to the social order. The term originated in England in the late 18th century, initially referring to those advocating for a drastic expansion of voting rights.1

In France, "radical" was used as a substitute for "republican" when open advocacy of republicanism was suppressed. French radicals generally favored legal means for fundamental reforms rather than outright revolution.2

The label "radical" has also been applied to Marxists and others advocating for violent social change, distinguishing them from gradualist reformers. In the United States, "radicalism" often implies political extremism, whether from the left or the right.1