What is the definition for least common factor?

Answer 1

All nonzero numbers have factors. Some numbers have some of the same factors as other numbers. These are common factors. All nonzero numbers have 1 as a factor. The least common factor of any set of positive integers is 1.

Answer 2

The Lowest Common Factor of any set of numbers is always 1 and therefore of not much practical use. It means the smallest number that can divide into all the members of a set of numbers evenly.

Answer 3

Do you mean lowest common multiple? If so it is the smallest multiple that the two numbers have in common