It's very hard for me to have an opinion about this question, firstly because I'm not familiar enough with the American culinary therminology, and secondly because the corresponding Italian terms of the words you mentioned actually have a different meaning.
A "salsa" (Italian word) is NOT just a "sauce". Our use of this term is more restricted and, independently from the ingredients, indicates something homogeneous and smooth, lacking solid parts. In example, a "tomato sauce" are tomatoes, cooked or not, with or without other ingredients, processed or pushed through a sieve to a cream.
If the "sauce" contains pieces of anything, it's a "Sugo". So, your "meat sauce" in Italian is "Sugo di Carne"..or "Ragù di carne", a term which language purists hate as it has been stolen from French with a wrong meaning (a "Ragout" in Italian is a "Spezzatino") but which is extensively used.
But..what do we Italians mean with the word "Ragù di carne"?
ANY pasta sauce made of meat, tomato and vegetables, independently from the cooking time (which, in any case, must be quite long) and the size of the meat pieces...I mean that "Ragù" is the Bolognese one, where the meat is minced, but ALSO the Ragù Napoletano and the "Tocco" Genovese, where a whole piece of meat is browned in oil and then cooked in tomato sauce with its gravy for many hours, after which you serve the "sauce" with pasta and the meat, sliced, as a main course (as you know, pasta in Italy is not considered a main course but a starter).
So, the recipe mentioned by Marmalady is a real Italian one, although our versions are usually less rich in different meat types.
So, maybe I'm wrong but if you say "Gravy" I think to something without tomato and not to a "Ragù", a word that personally I'd translate with "Meat Sauce"...