"Unistasis" is not a recognized scientific or biological term. It's possible you've encountered a misspelling or a term that's specific to a certain field or context.

Could you please provide more information about where you came across this term? Knowing the source or context might help me understand what it refers to.

For example:

* Where did you see it? (A book, website, conversation, etc.)

* What was the context? (What was being discussed?)

With more information, I can help you figure out what "unistasis" might mean.