D defs.my
Entry 4 senses · 2 variants Webster, 1913

Factorial

· Fac·to·ri·al · IPA /fækˈtɔːɹi.əl/
01 a. Of or pertaining to a factory.
  1. 1.
    Of or pertaining to a factory.
  2. 2.
    Related to factorials.(Math.)
02 n. 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 impart…
  1. 1.
    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.(Math.)
  2. 2.
    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.