I. adjective
1.
Synonyms: fundamental 1, basal, basic, bottom, foundational, meat-and-potatoes, primary, underlying
Related Word: cardinal, essential, vital; constitutional, inherent, intrinsic
Antonyms: superficial
2.
Synonyms: extreme 3, extremist, fanatic, rabid, revolutional, revolutionary, revolutionist, ultra, ultraist
3.
Synonyms: liberal 3, advanced, broad, broad-minded, progressive, tolerant, wide
II. noun
one who favors rapid and sweeping changes
the radicals advocated overthrow of the government
Synonyms: extremist, revolutionary, revolutionist, ultraist; compare reactionary
Related Word: liberal, progressive, reformer; agitator, insurgent, insurrectionist, rebel; anarchist, nihilist, red, subversive; out-and-outer; secessionist, separatist
Contrasted words: bitter-ender, diehard, fogy, intransigent, mossback, reactionary, rightist, standpatter
Antonyms: conservative