Please forgive this incredibly lame question, but if I have factor $n$ of $x,$ and I find its complementary factor $y= \frac xn$, does that complementary factor $y$ have a specific name?
I haven't been able to find one.
EDIT: As I mention in a comment below, I'm not trying to understand the concept; I'm looking for a piece of jargon that will make it easier to write a terse but descriptive function identifier.
EDIT 2: As @timtfj indicates in their comment directly beneath this question, I'm talking about a symmetrical term, not a unidirectional term such as "quotient". It seems (again based on comments) that "complementary factor" is acceptable, but I'm leery of writing my own answer to this question.
In line with some of the comments I've received, I'm going to stick with "complementary factor".
As @Clayton points out in one such comment, "cofactor" has an entry on Wikipedia congruent with my requirement. In fact, it seems "co-" as a prefix is a common shortening of "complementary" in this regard.
However – again, as @Clayton points out – "cofactor" tends to evoke matrices, so to avoid any potential ambiguity I will use the full form.
Many thanks to everybody who weighed in!