* A misspelling: It might be a misspelling of "illy," which is a slang term used in British English to mean poorly, badly, or not well. For example: "I'm feeling a bit illy today."
* A name: It could be a shortened version of a name like "Illyria" or "Ilyas."
* A brand: "Illy" is a well-known brand of Italian roasted coffee.
* A slang term: Depending on the context, it could be a slang term with a regional or specific meaning.
To clarify what "illy" means, please provide more context! What is the sentence or situation in which you encountered this word?