Is there a noun form of distinguishing?

There isn't a single perfect noun form of "distinguishing." However, depending on the context, you could use a few options:

General Distinguishing:

* Distinction: This is the most common and versatile option. It refers to a noticeable difference or a quality that makes something unique.

* Differentiation: This emphasizes the act of making something different or unique.

* Discrimination: This emphasizes the ability to recognize differences. However, it can have negative connotations, so use it carefully.

Specific Distinguishing:

* Distinctive feature: This highlights a specific characteristic that makes something unique.

* Mark of distinction: This refers to a feature that sets something apart in a positive way.

* Identifying characteristic: This emphasizes a feature that helps identify something.

The best choice will depend on the specific context and what you want to emphasize.