A moniker for the word anus. Fennel is a vegetable available at most supermarkets, which just so happens to share the PLU code as anise: a similar vegetable. Anise sounds like anus, which is why fennel=anus.
Note: the PLU code is 4515, which is also used in place of the word anus.
Kevin: Did you pick up any fennel at the supermarket?
Mark: No, that's disgusting.
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