radical

1 being very far from the center of public opinion the baggy trousers that Amelia Bloomer introduced in the 1850s were considered a radical form of dress for women at the time Synonyms extremist, fanatic (or fanatical), rabid, extreme, revolutionary, revolutionist, ultraRelated Words subversive, violent, wild; reactionaryNear Antonyms conservative, moderate, temperate; conventional, orthodox, traditional; liberal, progressiveAntonyms middle-of-the-road, nonrevolutionary, unrevolutionary

2 not bound by traditional ways or beliefs radical proponents of spelling reform would have every word spelled “just the way it sounds” Synonyms broad-minded, nonconventional, nonorthodox, nontraditional, open-minded, progressive, liberal, unconventional, unorthodoxRelated Words advanced, contemporary, modern; forbearing, indulgent, large-minded, lenient, permissive, tolerant; extreme; impartial, objective, unbiasedNear Antonyms hard, rigid, strict; doctrinal, dogmatic (also dogmatical); bigoted, blinkered, intolerant, narrow-minded; reactionary, unreconstructedAntonyms conservative, conventional, hidebound, nonprogressive, old-fashioned, orthodox, stodgy, traditional

3 slang  of the very best kind surfing conditions at virtually all of the beaches along the coast were truly radical Synonyms A-OK, A1, awesome, bang-up, banner, beautiful, blue-chip, blue-ribbon, boffo, bonny (also bonnie) [chiefly British], boss [slang], brag, brave, bully, bumper, capital, choice, classic, cool [slang], corking, crackerjack, cracking, dandy, divine, dope [slang], down [slang], dynamite, fab, fabulous, famous, fantabulous [slang], fantastic, fine, first-class, first-rate, first-string, five-star, four-star, frontline, gangbusters (also gangbuster), gilt-edged (or gilt-edge), gone [slang], grand, great, groovy, heavenly, high-class, hot, hype [slang], immense, jim-dandy, keen, lovely, marvelous (or marvellous), mean, neat, nifty, noble, number one (also No. 1), numero uno, out-of-sight [slang], par excellence, peachy, peachy keen, phat [slang], prime, primo [slang], prize, prizewinning, quality, excellent [slang], righteous [slang], sensational, slick, splendid, stellar, sterling, superb, superior, superlative, supernal, swell, terrific, tip-top, top, top-flight, top-notch, top-of-the-line, topping [chiefly British], top-shelf, unsurpassed, wizard [chiefly British], wonderfulRelated Words acceptable, adequate, all right, decent, good, OK (or okay), passable, satisfactory, tolerable; better, exceptional, fancy, high-grade, high-test, premium, select, special, superfine; classical, standard, traditionalNear Antonyms bad, inferior, low-grade, substandard, unsatisfactory; mediocre, middling, second-class, second-rateAntonyms atrocious, awful, execrable, lousy, pathetic, poor, rotten, terrible, vile, wretched