How are basin, washbowl and washpan different? We also have falling basin wiki referring to the thing as washpan. And then there's also washtub which I'd assume is more rectangular rather than round and is used for washing clothes instead of bathing.
I think there should also be distinction between the wooden Japanese style ones such as post #7903999 and the more commonly seen metal/plastic ones like post #7961311 and post #158975