Character from Greece, part of a fearsome gang (5)
I believe the answer is:
omega
'character from greece' is the definition.
'omega' can be an answer for 'character' (letter of the Greek alphabet). I'm not certain of the 'from greece' bit.
'part of a fearsome gang' is the wordplay.
'part of' indicates a hidden word.
'OMEGA' is hidden within 'fearsome gang'.
Can you help me to learn more?
(Other definitions for omega that I've seen before include "End of sequence" , "16 letter" , "in Greece, the limit!" , "symbol of resistance?" , "letter from abroad" .)