Merriam-Webster's Dictionary and Thesaurus - Merriam-Webster [517]
field marshal noun : an officer (as in the British army) of the highest rank
field–test verb : to test (as a new product) in actual situations reflecting intended use
— field test noun
fiend noun 1 : DEVIL 1
2 : an infernal being : DEMON
3 : an extremely wicked or cruel person
4 : a person excessively devoted to a pursuit 5 : one who is addicted esp. to a substance : ADDICT — fiend·ish·ly adverb Synonyms [2] demon, devil, ghoul, imp—more at DEMON [3] beast, devil, evildoer, rascal, reprobate, rogue, villain—more at VILLAIN [4] addict, enthusiast, fan, fanatic, freak, lover, maniac, nut—more at FAN [5] addict, doper, user—more at DOPER fiend·ish adjective : perversely diabolical Synonyms demonic, devilish, diabolical, satanic; also hellish, infernal; baleful, evil, sinister; malevolent, malicious, malignant; heinous, monstrous; barbarous, cruel, ferocious, inhuman, savage, vicious Antonyms angelic fierce adjective fierc·er; fierc·est 1 : violently hostile or aggressive in temperament 2 : given to fighting or killing : PUGNACIOUS 3 : marked by unrestrained zeal or vehemence : INTENSE 4 : furiously active or determined 5 : wild or menacing in appearance — fierce·ly adverb Synonyms [1] fell, ferocious, grim, savage, vicious; also bellicose, belligerent, pugnacious, warlike; contentious, quarrelsome, truculent; menacing, threatening; bestial, brute, inhuman, inhumane; barbaric, uncivilized, wild; heartless, implacable, merciless, pitiless, relentless, ruthless, unrelenting, wanton; bloodthirsty, bloody, murderous; rapacious, ravenous, voracious Antonyms gentle, mild [3] explosive, ferocious, furious, intense, terrible, vehement, vicious, violent—more at INTENSE [4] aggressive, ambitious, assertive, enterprising, go-getting, high-pressure, militant, self-assertive—more at AGGRESSIVE [5] austere, forbidding, grim, rough, rugged, severe, steely, stern—more at GRIM fierce·ness noun : the quality or state of being fierce Synonyms aggressiveness, assertiveness, emphasis, intensity, vehemence—more at VEHEMENCE fi·ery adjective fi·er·i·er; -est 1 : consisting of fire 2 : on fire : BURNING, BLAZING 3 : FLAMMABLE 4 : hot like a fire 5 : RED 6 : full of emotion or spirit 7 : IRRITABLE — fi·eri·ness noun Synonyms [2] ablaze, afire, burning—more at ABLAZE [4] broiling, burning, hot, torrid—more at HOT [6] ardent, emotional, fervent, feverish, hot-blooded, impassioned, passionate, red-hot, spirited—more at FERVENT fi·es·ta noun [ORIGIN: Sp] : a time of celebration marked by special observances : FESTIVAL Synonyms carnival, celebration, festival, festivity, fete, gala, jubilee—more at FESTIVAL fife noun [ORIGIN: G Pfeife pipe, fife] : a small flute FIFO abbreviation first in, first out fif·teen noun : one more than 14 — fifteen adjective or pronoun — fif·teenth adjective or noun fifth noun 1 : one that is number five in a countable series 2 : one of five equal parts of something 3 : a unit of measure for liquor equal to 1/5 U.S. gallon — fifth adjective or adverb fifth column noun : a group of secret supporters of a nation's enemy that engage in espionage or sabotage within the country — fifth columnist noun fifth wheel noun : one that is unnecessary and often burdensome fif·ty noun, plural fifties : five times 10 — fif·ti·eth adjective or noun — fifty adjective or pronoun fif·ty–fif·ty adjective 1 : shared equally 2 : half favorable and half unfavorable 1fig noun : a soft usu. pear-shaped edible fruit of a tree related to the mulberry; also : a tree bearing figs 2fig abbreviation 1 figurative; figuratively 2 figure 1fight verb fought ; fight·ing 1 : to contend against another in battle or physical combat 2 : BOX 3 : to put forth a determined effort 4 : to contend in disagreement or competition