* A slang term: Perhaps you heard someone use "chubby" as a playful or informal name for a language they were learning or struggling with.
* A fictional language: It's possible you're thinking of a language created for a book, movie, or game.
To help me understand what you're looking for, please provide more context. For example:
* Where did you hear the term "Chubby Language"?
* What were you doing when you heard it?
* Did you see it written anywhere?
With more information, I can help you figure out what you're thinking of.