reason

Noun

• a fact that logically justifies some premise or conclusion
  • there is reason to believe he is lying
    

• a justification for something existing or happening
  • he had no cause to complain
    
  • they had good reason to rejoice
    

• the state of having good sense and sound judgment
  • his rationality may have been impaired
    
  • he had to rely less on reason than on rousing their emotions
    

• the capacity for rational thought or inference or discrimination
  • we are told that man is endowed with reason and capable of distinguishing good from evil
    

• an explanation of the cause of some phenomenon
  • the reason a steady state was never reached was that the back pressure built up too slowly
    

• a rational motive for a belief or action
  • the reason that war was declared
    
  • the grounds for their declaration
    

Verb

• think logically
  • The children must learn to reason
    

• present reasons and arguments

• decide by reasoning; draw or come to a conclusion
  • We reasoned that it was cheaper to rent than to buy a house
    

Related words

• Synonyms: 
  cause , grounds , rationality , reasonableness , understanding , intellect , ground , argue , reason out , conclude