>AFIK, polymorphism means that when a method is sent to various kind of
>objects, the behavior is determined by the invoked objects themselves.

Indeed. Look at your statement carefully, you do not mention whether this
has to be done at compile-time or run-time.
Method overloading, templates etc are all examples of compile-time
polymorphism, simply because the correct code is determined at compile-time.
[In c++, it is entirely possible to declare a virtual method as inline for
example, and the compiler will inline it when there is no doubt as to which
method is going to be called]

>What Maurice means is 'method overloading', isn't it?

Well, yeah, I did say that...(hint: read then post)