Eastern game revealing self-confidence (3)
I believe the answer is:
'self-confidence' is the definition.
(I've seen this before)
'eastern game' is the wordplay.
'eastern' becomes 'e'.
'game' becomes 'go' (go is a kind of game).
'revealing' acts as a link.
(Other definitions for ego that I've seen before include "Conscious mind" , "Self-esteem or self-importance" , "One's self-image" , "Part of the mind" , "See 21 Down" .)