affecting or involving the basic nature or composition of something; fundamental
have made radical changes
marked by a considerable departure from the usual or traditional; innovative
of surgery: designed to remove the root of a disease or all diseased tissue
radical surgery
favouring or making tending to make extreme changes in existing views, habits, conditions, or institutions
a radical reformer
of or denoting being a political group associated with views, practices, and policies of extreme change
advocating extreme measures to attain a political end
the radical right
ofrelating to or involving a mathematical or linguistic root
of or being a linguistic form from which others have derived
of or growing from the root or the base of a stem
belonging to the root of a musical chord
chiefly NAmer, informal excellent or admirable