overload

Overloading a function or operator means the same function name or operator symbol can have different parameters. For example, if you say a 3D vector equals another 3D vector, like (1,2,3), that's pretty clear. But you could use the equals operator to say your 3D vector equals a single number, like 1. In that case, maybe the 3D Vector gets set to (1,1,1), but the overloading part is that there are multiple "3D Vector =" operators with different parameters. The language would have to look at the context to see which one to use.