n.
In politics, one who desires extreme change of part or all of the social order.
The term (which derives from the Latin word for "root," and thus implies change beginning at a system's roots) was given this sense by Charles James Fox in 1797 when he demanded "radical reform" consisting of universal manhood suffrage. In France before 1848, republicans and advocates of universal male suffrage were called radicals. The term was later applied to Marxists (see Marxism ) who called for fundamental social change to eradicate divisions among social classes. In popular usage, it is applied to political extremism, not necessarily violent, of both the left and the right.