All 5 Uses

factor
in
Breaking Dawn, by Meyer
(Auto-generated)

But I'd never factored a daughter into the equation.
Book 3 *

factored = considered (for affect on a result or outcome)
We are more closely bonded, and that's a factor, but not a huge one.†
Book 3 *

factor = thing that affects a result or outcome
Not really a motivating factor, if you know what I mean.†
Book 2
Was that what was going on, the mystery factor that was bonding the two of them?†
Book 2
Underneath that disbelief, I could see right away that this was the critical factor.†
Book 2

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.