rational in WordNet English dictionary

1. of or associated with or requiring the use of the mind
   "intellectual problems"; "the triumph of the rational over the animal side of man"
   intellectual  rational  noetic 
   
2. consistent with or based on or using reason
   "rational behavior"; "a process of rational inference"; "rational thought"
   rational 
   
3. capable of being expressed as a quotient of integers
   "rational numbers"
   rational 
   
4. having its source in or being guided by the intellect (as distinguished from experience or emotion)
   "a rational analysis"
   rational 
   

1. an integer or a fraction
   rational number  rational