n.  1.  (Math.) The relation which one quantity or magnitude has to another of the same kind. It is expressed by the quotient of the division of the first by the second; thus, the ratio of 3 to 6 is expressed by  
2.  Hence, fixed relation of number, quantity, or degree; rate; proportion;

Noun  1.  ratio  the relative magnitudes of two quantities (usually expressed as a quotient) 