The Italians that migrated over years ago called it both. My Godmother was from Milan and my Godfather was from Calabria and both of them called it gravy. My own mother called it sauce, so really, it is the same thing. The only thing it had to be was homemade, from the finest ingredients! :) Of that, they were united in thought.
I changed over to sauce years ago, but, slip back to the gravy when I go back home.
I have been looking for an update on all the Quillfires! You dashed off on to personal business and I just wanted to make sure all was as well as could be?