It's possible that:
* It's a misspelling: There may be a similar word you're thinking of. Double check the spelling.
* It's a regional dialect: It could be a word or phrase specific to a certain region of France or another country.
* It's a made-up name: It could be a fictional name or a personal name with no established meaning.
To find out the meaning, please provide more context:
* Where did you encounter this word? Was it in a book, a movie, a song, or online?
* What was the surrounding text or context?
With more information, I can help you understand the meaning of "La Jamelles."