radical
1. rad.i.cal \'rad-i-k*l\ aj [ME, fr. LL radicalis, fr. L radic-, radix
root - more at (MROOT 1: of, relating to, or proceeding from a root 2: of
or relating to the origin : FUNDAMENTAL 3a: marked by a considerable
departure from the usual or traditional : (MEXTREME 3b: tending or disposed
to make extreme changes in existing views, habits, conditions, or
institutions 3c: of, relating to, or constituting a political group
associated with vie ws, practices, and policies of extreme change -
rad.i.cal.ness n
2. radical n 1a: a root part 1b: basic principle : FOUNDATION 2a: ROOT
2b: a sound or letter belonging to a radical 3: one who is radical 4a: a
single replaceable atom or the reactive atomic form of an element 4b: a
group of atoms that is replaceable by a single atom, that is capable of
remaining unchanged during a series of reactions, or that may show a
definite transitory existence in the course of a reaction 5a: RADICAL
EXPRESSION 5b: RADICAL SIGN