Below are possible answers for the crossword clue Rigorous.
8 letter answer(s) to rigorous
EXACTING
claim as due or just; "The bank demanded payment of the loan"
having complicated nutritional requirements; especially growing only in special artificial cultures; "fastidious microorganisms"; "certain highly specialized xerophytes are extremely exacting in their requirements"
requiring precise accuracy; "an exacting job"; "became more exigent over his pronunciation"
severe and unremitting in making demands; "an exacting instructor"; "a stern disciplinarian"; "strict standards"
take as an undesirable consequence of some event or state of affairs;
THOROUGH
painstakingly careful and accurate; "our accountant is thorough"; "thorough research"
performed comprehensively and completely; "an exhaustive study"; "made a thorough search"; "thoroughgoing research"