rigor

1 something that is a cause for suffering or special effort especially in the attainment of a goal <hard-bitten folk who survived many rigors on the way to the promised land> Synonyms adversity, asperity, hardness, hardship, difficultyRelated Words discomfort, inconvenience, nuisance; affliction, trial, tribulation; knock, misfortune, mishap, tragedy; bar, catch, check, clog, crimp, embarrassment, handicap, hindrance, hitch, hurdle, impediment, interference, let, manacle, obstacle, obstruction, pons asinorum, rub, shackle, snag, stop, trammel; block, chain, deterrent, encumbrance, fetter, inhibition; humpNear Antonyms advantage, break, opportunity

2 the quality or state of being demanding or unyielding (as in discipline or criticism) <after being coddled by his former coach, the swimmer was shocked by the rigor of the new training program> Synonyms exactingness, hardness, harshness, inflexibility, rigidity, rigidness, severity, rigorousness, sternness, strictness, stringencyRelated Words callousness, hard-heartedness, implacability, obduracy, obdurateness, pitilessness; dourness, gruffness; asceticism, austereness, austerity, monasticism; determination, firmness, resolve, steadfastness; obstinacy, stubbornnessNear Antonyms forbearance, indulgence, kindness, lenience, patience, softness, tenderness, tolerance; responsiveness, willingness; compliance, pliability, pliancyAntonyms flexibility, gentleness, laxness, mildness

3 the quality or state of being very accurate <said that she had heard that excuse a million times, but then she was never known for the rigor of her calculations> Synonyms accuracy, accurateness, closeness, delicacy, exactitude, exactness, fineness, nicety, perfection, preciseness, precision, rigorousness, ultraprecision, veracityRelated Words correctness, fidelity, rightness, strictness, truth; definiteness, definitiveness, definitude, determinacy; nicety, subtlety; care, carefulness, fastidiousness, meticulousness, persnicketinessNear Antonyms approximation, roundness; falseness, falsity, incorrectness, wrongness; carelessness, guesswork, looseness; indefiniteness, vaguenessAntonyms coarseness, impreciseness, imprecision, inaccuracy, inexactitude, inexactness, roughness