Longman Dictionary of Contemporary English homepage

Date: 1300-1400
Language: Latin
Origin: rationalis, from ratio; RATIO

rational

 adjective
     
ra‧tion‧al
1 rational thoughts, decisions etc are based on reasons rather than emotions [≠ 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 a rational person is able to think calmly and sensibly [≠ 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 noun [uncountable]
Definition from the Longman Dictionary of Contemporary English
Advanced Learner's Dictionary.

Dictionary pictures of the day
Do you know what each of these is called?
What is the word for picture 1? What is the word for picture 2? What is the word for picture 3? What is the word for picture 4?
Click on any of the pictures above to find out what it is called.

Explore our topic dictionary

Browse the dictionary