[joshred]

Hey quibbler, you defend a castle (not a moat).

[netcan]

In the spirit of quibbling:

Moat: from Medieval Latin mota: “a mound, hill, a hill on which a castle is built, castle, embankment, turf”

In the spirit of mixed metaphors: </checkmate>

business catchphrase for the 20s: stock your hill with crocodiles

[ben509]

I was wondering what the heck dictionary you found that definition in, but then I realized you're conflating the etymology with the definition.