Musk overwhelming Greek character - and another (7)
I believe the answer is:
epsilon
'and another' is the definition.
I can't judge whether this defines the answer.
'musk overwhelming greek character' is the wordplay.
'musk' becomes 'Elon' (Elon Musk).
'overwhelming' is an insertion indicator.
'greek character' becomes 'psi' (letter from the Greek alphabet).
'elon' going around 'psi' is 'EPSILON'.
Can you help me to learn more?
(Other definitions for epsilon that I've seen before include "foreign letter" , "5th letter of the Greek alphabet" , "One's lip (anag)" , "Greek character" , "Fifth letter of the Greek alphabet" .)