rigorous

1 given to exacting standards of discipline and self-restraint a rigorous football coach who pushes his players to their physical and mental limits Synonyms austere, authoritarian, flinty, hard, harsh, heavy-handed, ramrod, rigid, severe, stern, strict, toughRelated Words demanding, exacting; uncharitable, unforgiving; adamant, adamantine, callous, hardened, hard-hearted, hard-line, immovable, implacable, inflexible, merciless, ossified, pitiless, relentless, rock-ribbed, stiff, unbending, uncompromising, unrelenting, unsparing, unyielding; dour, gruff; ascetic (also ascetical), monastic, monkish; browbeating, bullying; determined, firm, resolved, single-minded, steadfast, unflinching; dogged, intractable, obstinate, relentlessNear Antonyms easy, easygoing, laid-back, undemanding; charitable, kind, merciful, mild, patient, soft, softhearted; accepting, compromising, yielding; responsive, willing; acquiescent, agreeable, amenable, complaisant, compliant, flexible, pliable, pliantAntonyms clement, forbearing, gentle, indulgent, lax, lenient, tolerant

2 meeting the highest standard of accuracy a rigorous analysis of the data Synonyms accurate, close, delicate, exact, fine, hairline, mathematical, pinpoint, refined, precise, spot-onRelated Words correct, right, strict, true; definite, definitive; nice, subtle; careful, fastidious, finical, finicky, meticulousNear Antonyms approximate, round; false, incorrect, untrue, wrong; careless, loose; indefinite, unclear, vague; doubtful, dubious, questionable, unreliable, untrustworthyAntonyms coarse, imprecise, inaccurate, inexact, rough

3 not allowing for any exceptions or loosening of standards a rigorous diet and exercise regimen Synonyms brassbound, cast-iron, exacting, hard-line, inflexible, rigid, strict, stringent, uncompromisingRelated Words close, conscientious, exact, fussy, meticulous, painstaking, punctilious, scrupulous, undeviating; adamant, adamantine, determined, dogged, firm, relentless, resolved, single-minded, steadfast, stubborn, tenacious, unbending, unflinching; immovable, implacable, unappeasable, unrelenting, unsparing, unyielding; austere, demanding, flinty, grim, hard, hardened, hard-hearted, harsh, ironbound, severe, stern, toughNear Antonyms acquiescent, compliant, compromising, pliable, pliant, relenting, yielding; easy, easygoing, gentle, indulgent, kindly, lenient, merciful, mild, pampering, soft, spoiling, tolerant; neglectful, negligent, remiss, slipshod, sloppy, slovenly, unfussyAntonyms flexible, lax, loose, relaxed, slack

4 requiring considerable physical or mental effort studied for umpteen months for the rigorous exam Synonyms arduous, Augean, backbreaking, challenging, demanding, difficult, effortful, exacting, formidable, grueling (or gruelling), heavy, hellacious, herculean, killer, laborious, moiling, murderous, pick-and-shovel, hard, rough, rugged, severe, stiff, strenuous, sweaty, tall, testing, toilsome, tough, uphillRelated Words abstract, abstruse, complex, complicated, elusive, hairy, insoluble, intricate, involved, knotty, opaque, problematic (also problematical), recondite, serious, spiny, stubborn, thorny, ticklish, tricky; bruising, burdensome, exhausting, labored, onerous, oppressive, stressful, taxing, tight, trying; annoying, bothersome, distressing, irksome, troublesome, vexatious; grievous, grim, strict, stringent; brutal, cruel, inhuman, painfulNear Antonyms achievable, clear, doable, elementary, manageable, uncomplicated; comforting, gentle, painless, relaxed, smooth, soothing; accessible, friendly, idiotproof, user-friendlyAntonyms cheap, easy, effortless, facile, light, mindless, simple, soft, undemanding