Longman Dictionary of Contemporary English - rigour

~ BrE rigor AmE n 1 the rigours of the problems and unpleasant conditions of a difficult situation  (all the rigours of a Canadian winter) 2 BrE formal strictness or severity of a punishment  (He deserves to be punished with the full rigour of the law.) 3 great care and thoroughness in making sure that something is correct  (Their research seems to me to be lacking in rigour.)