I like to phrase it like this: “A parameter is a local variable that's initialized by passing an argument”. That works for functions and C++ templates. It also works in languages like ML, where you can initialize multiple parameters from a single argument (via pattern matching).

Consequently, speaking of “passing a parameter” is dead wrong most of the time, except maybe when you're writing a function that “defines” other functions, where a parameter of the function to be defined is an argument of the definer function. But I will stop here before it gets complicated.