jim rozen writes:

I repeat that "lossy" means "attributable to the device", whether or not
the device itself gains the waste heat.

This is a counter-intuitive definition. Few would
accept it as reasonable.

No, it is the only appropriate definition.

You use a hose, you *lose* some power "in the hose". Hoses are lossy. The
longer and skinnier they are, the more lossy they are. The hose doesn't
get hot, though. A regulator is just a short hose that gets skinny or fat.