I don't know where the name itself came from. Probably because it's similar to a name like Lurch.
The name itself wasn't even IN the movie. "Lurtz!" cried Boromir. "I should have KNOWN it was you!" "Yes," growls Lurtz. "I've wanted to do this for so long, Boromir. So long..."
It's worth mentioning though that there is a reason there's a chieftian uruk, instead of just a band of them. Peter Jackson wanted Boromir's death to be a little more worth something than just slain by a mindless orc, and to be killed by the leader of the entire force made it a little more worthwhile. And for Aragorn to take a whack at.