How should we define “employee engagement?”

There seem to be articles on this topic going back to 2010 and even before that. I’m not going to link them. There’s also probably half a million supposed “thought leadership” pieces on what exactly employee engagement is, with a newer term — “employee experience” — coming in periodically.
You’re talking about these terms now having been around for 9–10 years, if not longer. I still do…