none of (one's) business(redirected from None Of Their Business)
Also found in: Acronyms.
none of (one's) business
Something that is of no concern to another. It's really none of his business what I do with the money I earn.
none of someone's business
not of someone's concern. (A gentle rebuke.) Q: When are you going to leave for home? A: None of your business. How I managed to afford all this is none of your business.