Weh lived in a modern house in the late 60’s. The words we used were “Front Room” and “Family Room”, but I also remember the term “rumpus room”.
In our house (modern then), the “Front Room” did get used. It contained my dad’s leather chair, and my mother’s rocker, a bookcase and a record player, so it was were we kids read and played records. I think dad probably read the paper and listened to the radio in that room. It wasn’t closed off, because in the ‘modern’ house, there was no door from the front hallway, and it was divided from the ‘dining room’ by some kind of 3/4 height storage partition, with another open passage.
The ‘Family room’ with the TV adjoined the kitchen, separated by a low breakfast bar.