What is Abbreviation for single?

There isn't a universally accepted abbreviation for "single" in the same way that there is for "married" (M).

However, depending on the context, you could use these abbreviations:

* S: This is a common abbreviation used in some forms and databases, especially for relationship status.

* Sg: This abbreviation is less common but sometimes used in formal contexts.

* SL: This is used sometimes in dating profiles.

It's important to note that the use of these abbreviations is not always standardized, so it's best to clarify the meaning in the context where you are using them.