Green’s Dictionary of Slang

Uncle Bert n.

a shirt.

1971		J. Jones Rhy. Cockney Sl.
2002		K. Lucas ‘All my life I’ve Wanted to Be a Barrow Boy’ in Obfuscation News Apr. Issue 20 🌐 No my old Cock Sparrow, but Rob gave me this lovely roll of Purple cloth and it seemed a shame not to use it and save you some Bees and Honey. Look you can have it for an Aristole of Gay and Frisky. Not only that I will throw in an Uncle Bert as well.