Back a long long time ago when I was a single girl...
I had been out on a date or two, maybe lunch, coffee, or a after work drink... that was casual seeing someone, implying some interests....
If I had been out on several dates with someone, and had started making plans for more dates, then I was dating them not necessarily exclusive
Once it got to the point of being exclusive with someone... then boyfriend and girlfriend came into play.. and we were in a relationship..
Terms like hanging out... to me means hanging out... friendship, no romantic interest, and might could develop into more kinda just, sorta seeing if there is maybe something a little bit more... for me if I said, we are just hanging out... for me that meant I was just interested in being friends...