GNU Collaborative International Dictionary of English

Found 2 definitions

1.       
   Factorial (?), a.
   1. Of or pertaining to a factory.  Buchanan.
   
   [1913 Webster]
   
   
   2. (Math.) Related to factorials.
   
   [1913 Webster]
   
   
         
       

2.       
   Factorial, n. (Math.) (a) pl. A name given to the factors of a continued product when the former are derivable from one and the same function F(x) by successively imparting a constant increment or decrement h to the independent variable. Thus the product F(x).F(x + h).F(x + 2h) . . . F[x + (n-1)h] is called a factorial term, and its several factors take the name of factorials.  Brande & C.
   
   (b) The product of the consecutive whole numbers from unity up to any given number; “thus, 5 factorial is the product of 5 times four times three times two times one, or 120”.
   
   [1913 Webster +PJC]