Hello, What's the exact meaning of "off" when used at a restaurant, café or other place that serves food? For example, I recall hearing "off" used in contexts similar to both of these: (Customer, looking at the menu: ) "May I have the rock cod, please?" (Waiter: ) "Sorry, rock cod is off today." or (Chef 1: ) "It looks like we have some rock cod in stock today -- let's make that today's special!" (Chef 2: ) "Sorry, the rock cod is off."