Could you provide more context? Perhaps you meant a similar word, or you're thinking of a specific work of fiction where "sleeno" appears.
For example:
* Did you mean "slumber" or "sleep" instead? These words relate to resting and being unconscious.
* Are you referring to a specific book, movie, or game? Knowing the source would help me understand what "sleeno" might refer to.
Please give me more information so I can help you! 😊