British slang from the 1950s thought to have originated in East Anglia and meaning a lesbian. The word oonch is thought to have derived from the dialect pronunciation of 'conch' and was used as a slang name for the vagina due to the resemblance of the opening of the female genitalia to the opening of a conch shell. Thus a lesbian became an oonch fancier.
"Ah! I wouldn't mind a bit of that!"
"Forget it boy! She's an oonch fancier."
Anyone who is into K-pop knows the title belongs to Kim Taehyung (V) of BTS because he always tops lists of "Most Viewed Fancams" on Youtube. He isn't just the most-watched in his group, but in K-pop as a whole.
"We all know V is the King of Fancams, but what's your favorite fancam?"
"Spring Day V Focus Fancam is the one I keep going back to."