Growing up in the 50’s my Italian family knew an Italian couple who used to differentiate between "red gravy" and "brown gravy" at their meals…we ate there a lot and I thought that was interesting. In our home,tomato sauce was simply "gravy" as was brown gravy…you knew what gravy it was by the neal you were eating!!!!
In italy they tell me no one calls sauce gravy…by the way"Ragu" simply means sauce!!!!