From Longman Dictionary of Contemporary Englishrationalra‧tion‧al /ˈræʃənəl/ ●●○ AWL adjective 1 LOGICALrational thoughts, decisions etc are based on reasons rather than emotions opp irrational Parents need to be fully informed so they can make a rational decision. I’m sure there’s a rational explanation for all this. It’s impossible to have a rational conversation with him.2 SENSIBLEa rational person is able to think calmly and sensibly opp irrational Culley was quite rational at the time of her baby’s death.3 formal able to make sensible judgments Man is a rational animal. —rationally adverb We were too shocked to think rationally. —rationality /ˌræʃəˈnæləlti/ noun [uncountable]COLLOCATIONSnounsa rational explanationI told myself that there must be some simple, rational explanation.a rational decision/choiceThe patient was incapable of making a rational decision.a rational approachWe must adopt a rational approach when dealing with this problem.a rational analysisEmotions are running so high that any rational analysis of the situation is difficult.rational thoughtBabies were thought to be incapable of rational thought.rational argumentNuclear weapons are so absurd that rational argument about their use is scarcely possible.a rational conversation/discussionLet's all calm down and have a rational discussion.adverbsperfectly rationalI'm sure there's a perfectly rational explanation.

Examples from the Corpus

rational• The talk was lively and, compared to Morrison's drivel, refreshingly rational.• Many of the patients have long histories of drug abuse, and they're not always rational.• People's behaviour isn't always purely rational.• Such beliefs serve to explain the system to its members: they make social inequality appear rational and reasonable.• We're looking for someone with a rational approach to dealing with problems.• rational behavior• From a rational choice perspective, you would be rather foolish to vote in a presidential election.• It should be seen as seven functional stages of the budgetary process which take place in a political or rational context.• Education helps us to make rational decisions.• Should they, then, be branded as spurious designators and banished from rational discourse?• There is no rational explanation for Melanie Hawkin's disappearance.• There must be some rational explanation for this apparently bizarre phenomenon.• Let's try and discuss this like two rational human beings.• How can a rational man be taken in by these arguments?• Consequently rational members of organizations are more likely to stay loyal and inactive than to be vocal participants.• There appears to be no rational motive for the attack.• Exactly how a rational person will solve it we shall show later on.• No rational person would have agreed to those terms.• Taking action to defend yourself is a completely rational reaction if you're being attacked.rational explanation• In any case, Amiss's mind was racing, grappling with a situation devoid of any rational explanation.• The subsequent references by the deceased to £17,000 as the value of his portfolio were not the subject of any rational explanation.• Through their various plights, the drama questions a world where feminine ideals regularly defy rational explanation.• There was a rational explanation for all this and, when Carol arrived, he'd discover what it was.• This is the mystery of sin which has no rational explanation, for it is ultimately and radically inexplicable.• Only now have scientists begun to offer rational explanations for this phenomenon.• Either way, there has to be some rational explanation of Clinton's conduct.• I told myself that there must be some simple, rational explanation, something Illingworth had overlooked.