* It's a misspelling: Check the context to see if it might be a misspelling of a common word or acronym.
* It's a personal or local abbreviation: It could be a shorthand used within a specific group or community.
* It's a made-up word: Sometimes people create words or acronyms for fun or personal use.
To understand what "u.a.r.k" means, you need more context. Please provide:
* The sentence or text where you found it.
* The topic or subject it relates to.
With more information, I might be able to help you decipher its meaning.