Heh, I didn't like to resort to already-made definitions, more about how people here perceive it .
I also think that when talking about ego-death experiences it's meant in the 2nd sense I used too ( note: ego is a greek-rooted word and it means "I" ) ego-loss : loss of "I".
And if it's talked as in self-esteem, usually it can get boosted as easily as it can be destroyed, after a psy experience.
Some might refer to ego as in opposition to our higher Self, so it gets even more complex than that.
I know one thing for sure(?), there's lots of cliche talk about ego etc, especially in the psy scene.