When it comes to expressing that something is not related or connected to another thing, there are a number of synonyms that can be used instead of the phrase "has nothing to do with." Some of these include "unrelated," "unconnected," "irrelevant," "inapplicable," "incidental," "extraneous," "superfluous," "unrelated to the matter at hand," "not pertinent," "not relevant," and "not germane." Each of these terms can provide a slightly different nuance or emphasis, and can be used to vary the language used in written or spoken communication. Experimenting with different synonyms can help to keep language fresh and interesting.