What does “yippie ki yay” mean?

Question

In the movie Die Hard, John McClane (Bruce Willis) says the line "Yippie Ki Yay".

What does this mean?

Answer 1

First time Bruce willis uses that term in Die hard series is when he speaks to Hans in walkie talkie. When Hans was asking him if he was another american cowboy inspired by John wayne and then Bruce willis says he is partial to Roy Rogers and ends his conversation with Yippie Kay Yay and swears after it.

The actual meaning of the phrase from the references i looked up means the phrase doesn't actually mean anything except its used a reference to an exclamation used by Cowboys in the old times.