A term of derision for supporters of Pompey FC. They are also known as skates because of their fishy persuasions ie: shagging fish when there are no women available (or in some cases even when there are). Codsnogging is a form of foreplay prior to fucking a skate.
How're you doing? Did you fuck that skate last night?
Nah, She reckons I'm a codsnogger. She said I smelt like fish.