Synonyms for radical

adjective

• (used of opinions and actions) far beyond the norm
• especially of leaves; located at the base of a plant or stem; especially arising directly from the root or rootstock or a root-like stem
• markedly new or introducing radical change
• arising from or going to the root or source
• of or relating to or constituting a linguistic root

noun

• an atom or group of atoms with at least one unpaired electron; in the body it is usually an oxygen molecule that has lost an electron and will stabilize itself by stealing an electron from a nearby molecule
• (linguistics) the form of a word after all affixes are removed
• (chemistry) two or more atoms bound together as a single unit and forming part of a molecule
• a character conveying the lexical meaning of a logogram
• a person who has radical ideas or opinions
• (mathematics) a quantity expressed as the root of another quantity