* It's a misspelling: You might be thinking of a similar word, like "length," "lengthen," or "leech."
* It's a technical term: It could be a term specific to a certain field or industry. If you can provide more context, I might be able to help.
* It's a made-up word: It's possible that you encountered this word in a fictional context, like a book or a game.
Please provide more context or details so I can help you figure out what "lenigh" might refer to.