Emotionally exhausted in triumph or defeat (8)
I believe the answer is:
overcome
This might be a double definition.
'emotionally exhausted in triumph' is the first definition.
'overcome' can be an answer for 'triumph' (I've seen this in another clue). I'm not sure about the 'emotionally exhausted in' bit.
'defeat' is the second definition.
(I know that defeat can be written as overcome)
'or' is the link.
Can you help me to learn more?
(Other definitions for overcome that I've seen before include "Vanquish" , "'Engulfed, by emotion say (8)'" , "Come over in order to conquer" , "Get the better of" , "Deal successfully with difficulties" .)