Also, the word “overshirt” seems to get used for a lot of what I’d just call “shirts” these days.
Nah, whilst they come from the same ‘family’ I’d say there is a distinct difference between the two such as:
– Usually a thicker/heavier material so it can act as a jacket (shacket)
– Cut a bit bigger to allow layering underneath
– Cut square at the bottom, not intended to be tucked in
– More pockets (often 2 x chest pockets and possibly hip / hand warmer pockets)
I can see how this may get confused with a thicker flannel shirt, but if your flannel has the above traits it’s probably an overshirt.