WordReference Random House Unabridged Dictionary of American English © 2015
(fak tôr′ē əl, -tōr′-), n.
Mathematics[Math.]of or pertaining to factors or factorials.
of or pertaining to a factor or a factory.
- Mathematics[Math.]the product of a given positive integer multiplied by all lesser positive integers: The quantity four factorial (4!) = 4 · 3 · 2 · 1 = 24. Symbol: n!, where n is the given integer.
Collins Concise English Dictionary © HarperCollins Publishers::
factorial /fækˈtɔːrɪəl/ n
- the product of all the positive integers from one up to and including a given integer. Factorial zero is assigned the value of one: factorial four is 1 × 2 × 3 × 4. Symbol: n!, where n is the given integer
- of or involving factorials or factors
'factorial' also found in these entries: