Andy Capp, n. — Green’s Dictionary of Slang

Andy Capp n.

[rhy. sl. = crap n.¹ (2); Andy Capp is a well-known strip cartoon character, created in 1956 by Reg Smythe for the Daily Mirror]

(Aus.) an act of defecation.

1984		J. Meredith Learn to Talk the Old Jack Lang 19: Andy Capp: a crap, to defecate .
2000		Aus. Sl. 🌐 Andie Capp / Andy Capp crap; defecate.
2002		Pete’s Aussie Sl. Home Page 🌐 Andy Capp: a crap, to defecate.