factorial

• POS: Adjective, Noun
• HYPHEN: fac=to=ri=al

CIDE DICTIONARY

factorial, a. 

•  Of or pertaining to a factory.  Buchanan.  [1913 Webster]
•  Related to factorials.  [1913 Webster]

factorial, 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 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.

OXFORD DICTIONARY

factorial, n. & adj. Math.
--n.
1 the product of a number and all the whole numbers below it (factorial four = 4 x 3 x 2 x 1).

Usage

Symb.: ! (as in 4!).
2 the product of a series of factors in an arithmetical progression.
--adj. of a factor or factorial.

Derivative

factorially adv.