General meanings:
* Field: This is a very common synonym for "domain" and can be used in most contexts.
* Area: Similar to "field", this implies a specific area of knowledge or activity.
* Sphere: This word suggests a wider scope or range of influence.
* Realm: This implies a specific area of control or authority.
Specific meanings:
* Website address: For this meaning, "URL" is the best synonym.
* Range of knowledge: You could use "expertise", "specialty", or "area of knowledge" as synonyms.
* Territory: This implies physical space controlled by something or someone.
* Scope: This refers to the extent or range of something.
* Jurisdiction: This implies legal or official authority.
* Province: This word suggests a particular area of responsibility.
It's important to consider the context when choosing a synonym for "domain" to ensure that the meaning is clear and appropriate.