What does to mean in British slang?

"To" in British slang doesn't have a specific meaning on its own. It's usually used as a part of a phrase or idiom where it takes on a different meaning.

Here are some examples:

* "To be on the sauce": To be drunk.

* "To have a chinwag": To have a conversation.

* "To be knackered": To be very tired.

* "To be a right laugh": To be very funny.

* "To be a bit of a tosser": To be a stupid or annoying person.

Remember: The meaning of "to" depends on the surrounding words and the context of the conversation.

If you can provide the full phrase or sentence where "to" is used, I can give you a more specific answer.