* There's a typo or misspelling: Double-check the spelling of the terms. Maybe "Bisva" is meant to be "Bishwa" or "Vishva," which means "world" or "universe" in some languages.
* It's a local or regional term: It might be specific to a particular community or region, and not widely known.
* It's a fictional concept: It could be a term used in a work of fiction, like a book, movie, or game.
To help you find what you're looking for, please provide more context:
* Where did you encounter this term? Was it in a book, online, in a conversation?
* What was the context? What was being discussed when this term was mentioned?
With more information, I might be able to assist you better.