* It's a regional slang term: It might be a local expression used in a specific area or community.
* It's a nickname: It could be a nickname for someone or something, but without more context, it's impossible to say who or what it refers to.
* It's a misheard phrase: It's possible you've misheard or misinterpreted a word or phrase.
* It's a made-up term: It might be a term invented for a specific story, game, or situation.
To help you understand what "mealy Jimmy" means, please provide more context:
* Where did you hear it?
* What was the situation?
* Who said it?
With more information, I can better help you understand the meaning of this phrase.