Immediately overwhelmed by alpha male, one in particular from a European capital (8)
I believe the answer is:
athenian
'one in particular from a european capital' is the definition.
'athenian' can be an answer for 'capital' (I have seen 'foreign capital' mean 'athenian' so perhaps 'capital' could also mean 'athenian'). I am not sure about the 'one in particular from a european' bit.
'immediately overwhelmed by alpha male' is the wordplay.
'immediately' becomes 'then'.
'overwhelmed by' is a charade indicator (letters next to each other) (in a down clue, some letters go on top of others).
'alpha' becomes 'a' (phonetic alphabet: alpha, bravo, charlie etc.).
'male' becomes 'ian' (I've seen this before).
'then' put after 'a' is 'athen'.
'athen'+'ian'='ATHENIAN'
Can you help me to learn more?
(Other definitions for athenian that I've seen before include "Is the Greek in AA then?" , "foreign capital" , "Inhabitant of Greece's capital" , "Native of Greek capital" , "Fellow-citizen of Pericles" .)