All 6 Uses

factor
in
The Fountainhead
(Auto-generated)

The senseless is the major factor in our lives.†
Chpt 2.12 *

factor = thing that affects a result or outcome
Well, if you consider the determining factor, which is, of course, economic...†
Chpt 4.10
The discipline of an immortal tradition has served here as a cohesive factor in evolving a structure whose beauty can reach, simply and lucidly, the heart of every man in the street.†
Chpt 1.4
Pressure is a powerful factor.†
Chpt 2.2
It just so happened that I chose the field that interests you—the field of art—because I thought that it focused the decisive factors in the task we had to accomplish.†
Chpt 4.7
Since we are merely the creatures of our chemical metabolism and of the economic factors of our background, there's not a damn thing we can do about anything whatever.†
Chpt 4.7

Definitions:

(1) (factor as in: It was the deciding factor.)
something that affects a result or outcome

You also may encounter x-factor or x factor--meaning "the most important thing that influences a result or outcome."
(2) (factor as in: factor it into your thinking)
include consideration of
(3) (meaning too rare to warrant focus)
There are many specialized meanings in fields such as mathematics, business, finance, biology, and grammar.