* A misspelling: Perhaps you meant "sinful," which describes something immoral or wrong.
* A foreign word: It could be a word from a different language that has no direct English translation. If you provide more context, I might be able to help you figure out what it means.
Please provide more information, such as:
* The context where you saw "sinsil." Was it in a book, a song, a conversation?
* What language do you think "sinsil" comes from?
With more information, I can help you understand the meaning of "sinsil."