Here are a few words that might be similar in meaning to "stop restrain," but aren't true homophones:
* Restrain - This is the most direct synonym, but it's spelled differently and has a slightly different emphasis (more about preventing movement).
* Hold back - This phrase has a similar meaning to "stop restrain" but isn't a single word.
* Check - This word can sometimes be used synonymously with "restrain," but it depends on the context.
Ultimately, the best word to use will depend on the specific situation.