rad· i· cal
ˈradək(ə)l/
adjective
1. (especially of change or action) relating to or affecting the fundamental nature of something; far-reaching or thorough.
"a radical overhaul of the existing regulatory framework”
synonyms: thoroughgoing, thorough, complete, total, comprehensive, exhaustive, sweeping, far-reaching, wide-ranging, extensive, across the
board, profound, major, stringent, rigorous
"radical reform”
2. advocating or based on thorough or complete political or social reform; representing or supporting an extreme section of a political party.
"a radical American activist”
synonyms: revolutionary, progressive, reformist, revisionist, progressivist;
noun
1. a person who advocates thorough or complete political or social reform; a member of a political party or part of a party pursuing such
aims.
synonyms: revolutionary, progressive, reformer, revisionist;
2. CHEMISTRY a group of atoms behaving as a unit in a number of compounds.