* It's a dialectal variation or a slang term: Kikuyu has several dialects, and some words might be unique to specific regions.
* It's a misspelling: Double-check the spelling. Maybe it's a similar word with a different spelling.
* It's a new or invented word: Sometimes new words are created for specific contexts.
To understand the meaning of "nyuba," please provide more context.
For example:
* Where did you encounter this word? (a book, a conversation, online)
* What was the context? (What were they talking about?)
With more information, I might be able to help you understand the meaning of "nyuba."