Fac*to"ri*al (?), a. 1.
Of or pertaining to a factory. Buchanan.
2. (Math.) Related to
factorials.
Fac*to"ri*al, 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 numbers
from unity up to any given number.