In generics, “extends” means “extends or implements”

The Java engineers had to give you a way to put a constraint on a parameterized type, so that you can restrict it to, say, only subclasses of Animal. But you also need to constrain a type to allow only classes that implement a particular interface. So here’s a situation where we need one kind of syntax to work for both situations—inheritance and implementation. In other words, that works for both extends and implements.

And the winning word was... extends. But it really means “is-a”, and works regardless of whether the type on the right is an interface or a class.