According to Wikipedia, the name 'Warcraft' was chosen for no particular reason other than that it sounded cool. The Wikipedia links to this article that discussed the origin of the name in more detail.
I played all of the games, except for the original Warcraft: Orcs & Humans, and I cannot remember I ever saw any in-universe text in which the word 'Warcraft' was used. There is the 'World of Warcraft', but in-universe that world is called 'Azeroth'.
Was there ever any in-universe text in any of the games (or otherwise in the books), e.g. a dialogue or quest description that used the name?