* A misspelling: Perhaps it's meant to be "underledge," which could be a misspelling of "underledge," referring to the bottom part of a ledge.
* A regional term: It might be a regional dialect word or slang term with a specific meaning in a particular place.
* A made-up word: It could be a newly invented word, possibly for a specific purpose or in a creative context.
To understand what "underledge" means, it's helpful to know the context in which you encountered it.
Please provide more information, such as:
* Where did you see the word? (e.g., in a book, a conversation, online)
* What was the surrounding text or conversation?
With more context, I can give you a more accurate answer.