In short, uncle who found snake in Greek capital, is releasing it (10)

'capital is releasing it' is the definition.
I can't judge whether this definition defines the answer.

'in short uncle who found snake in greek' is the wordplay.
I cannot really understand how this works, but
'in' is found in the answer.
'snake' could be 'asp' (asp is a kind of snake) and 'asp' is found in the answer.
'greek' could be 'g' (philological abbreviation) and 'g' is located in the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?