The Meaning of radical

• (a.) Of or pertaining to the root; proceeding directly from the root.
• (a.) Hence: Of or pertaining to the root or origin; reaching to the center, to the foundation, to the ultimate sources, to the principles, or the like; original; fundamental; thorough-going; unsparing; extreme; as, radical evils; radical reform; a radical party.
• (a.) Belonging to, or proceeding from, the root of a plant; as, radical tubers or hairs.
• (a.) Proceeding from a rootlike stem, or one which does not rise above the ground; as, the radical leaves of the dandelion and the sidesaddle flower.
• (a.) Relating, or belonging, to the root, or ultimate source of derivation; as, a radical verbal form.
• (a.) Of or pertaining to a radix or root; as, a radical quantity; a radical sign. See below.
• (n.) A primitive word; a radix, root, or simple, underived, uncompounded word; an etymon.
• (n.) A primitive letter; a letter that belongs to the radix.
• (n.) One who advocates radical changes in government or social institutions, especially such changes as are intended to level class inequalities; -- opposed to conservative.
• (n.) A characteristic, essential, and fundamental constituent of any compound; hence, sometimes, an atom.
• (n.) Specifically, a group of two or more atoms, not completely saturated, which are so linked that their union implies certain properties, and are conveniently regarded as playing the part of a single atom; a residue; -- called also a compound radical. Cf. Residue.
• (n.) A radical quantity. See under Radical, a.
• (a.) A radical vessel. See under Radical, a.

Synonyms

root , theme , root word , free radical , grouping , mathematical group , base , chemical group , group , stem , al-Qaeda , idea , groundwork , al-Qaida , ascendent , substructure , composition , paper , fundament , motif , prow , ascendant , basis , understructure , shank , stalk , nucleotide , report , foundation , etymon , subject , floor , bow , fore , topic , melodic theme , source , ancestor , foot , antecedent , musical theme , infrastructure , alkali , cornerstone , origin , pedestal , home , rootage , tooth root , base of operations , radix , stand , stem turn , solution , beginning , al-Qa'ida , bag , revolutionary , ultra , basal , extremist , rotatory , primary , complete , ingrained , perfect , constitutional , innate , positive , entire , native , primitive , essential , natural , thorough , extreme , organic , thoroughgoing , fundamental , original , total

Antonyms

moderate , cauline , old , incidental , inadequate , partial , superficial , trial , incident , conservative , incomplete , palliative , slight , tentative

Rhymes

radicle