Property of Positive/Negative

Question

Is there a word for whether something has the property of being positive or negative such as "parity" for being odd or even?

Answer 1

The word you are looking for is "sign". For instance, we would say $-5$ has negative sign, and $5$ has positive sign. The sign function is defined to be $x \mapsto |x|/x$ for $x \ne 0$.