This might be a silly question, but did the term "empath" exist at all before Star Trek: TNG aired? I do not recall ever seeing it in pre-1980s text but obviously I am limited by my perspective here. If the term was invented to describe Troi then that feels extremely appropriate for how it's used now actually (given it was probably popularised from this point, it probably still is, even if the paranormal crowd were using it earlier)