Ones unkempt, extremely unhygienic and at all times fishy smelling vagina. Typically consisting of fungal matter and a sewerage waste flavouring. Cod Box smell and taste is almost undistinguishable to that of a dutty poo pocket.
Roger: David texted me mid wank, he told me Lauren has a mingin Cod Box.
Lenny: Shut up fam, your mum has a barmy Cod Box.