rational

/ˈrash-nəl/

Middle English racional, from Anglo-French racionel, from Latin rationalis, from ration-, ratio

adjective

  1. having reason or understanding

  2. relating to, based on, or agreeable to reason : reasonable

  3. involving only multiplication, division, addition, and subtraction and only a finite number of times

a rational explanation

noun

  1. something rational; specifically : rational, number

noun

  1. a function that is the quotient of two polynomials; also : polynomial