Baronlando said:
http://filmsound.org/starwars/starwars-AQ.htm
Burtt says it's from 77. I don't think they say "star destoyer" in the final cut of the movie but there is pre-Empire material like comics and publicity stuff that use the name.
Han Solo said "Two Imperial Star Destroyers, I'm gonna try and outrun 'em" when they were escaping Tatooine.