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."
A classy-sounding way to refer to your anus.
The term comes from the Chicago-based chocolate company, Fannie May, because both need to make fudge every day and in a large variety.
After eating Indian food, I had fudge coming out of my fannie may like crazy.