* A personal or group-specific abbreviation: It could be a term used within a specific community, family, or group of friends.
* A typo or misspelling: It might be a mistake for a different acronym.
To figure out what "TTNY" means, you need more context.
Please tell me:
* Where did you see or hear this abbreviation?
* What was the surrounding text or conversation?
With more information, I might be able to help you understand what "TTNY" stands for.