It's possible that:
* It's a misspelling. Perhaps you meant a similar-sounding word like "Nyasaland" (a former British protectorate in Africa) or "Nisha" (a popular name in South Asia).
* It's a name. "Nyisha" could be a unique or uncommon name, potentially of African origin.
* It's a word from a specific language or dialect. It could be a word with meaning in a regional language or a specialized field.
To understand the meaning of "nyisha," you need to provide more context. Please tell me:
* Where did you encounter this word? (e.g., a book, a website, a conversation)
* What was the context? (e.g., what was the topic being discussed, what was the speaker's background?)
With more information, I might be able to help you determine the meaning of "nyisha."