Ego has been defined in many ways, and while I can understand Freud's model I much prefer Jung's -
"To Jung, the ego was the center of the field of consciousness, the part of the psyche where our conscious awareness resides, our sense of identity and existence. This part can be seen as a kind of “command HQ”, organizing our thoughts, feelings, senses, and intuition, and regulating access to memory. It is the part that links the inner and outer worlds together, forming how we relate to that which is external to us.
http://journalpsyche.org/jungian-model-psyche/

Spiritually, your reality is defined by your perceptions, your perceptions are defined by your beliefs and your beliefs are defined by your definitions so it all comes back to Jung's definition of the ego. Spirituality is often external to us, depending on your definitions of course. I was watching a YouTube recently of a TedTalk given by Anil Seth, whose multi-disciplinary team has yet to work out what consciousness is, but he generally agrees with Jung in that it's relating internal and external. According to Seth our perception of our reality is as much what's inside as it is outside. Regardless of how we define what ego is or isn't, regardless of how we define self, Self, Higher Self, True Self there's one thing that's inescapable, the aspect of ourselves that processes those definitions are the same aspect as the one that processes the 'mundane' functions of our existence.

The best way to understand ego is to ask the reasons for you holding your definition of ego, whatever that may be.

And before anyone mentions it, it's been scientifically proven that meditation is simply a shift in our brainwave patterns the same as... anything else.