Reading City mostly overwhelmed by Spanish team (7)
I believe the answer is:
recital
'reading' is the definition.
(I know that reading can be written as recital)
'city mostly overwhelmed by spanish team' is the wordplay.
'mostly' means to remove the last letter (most but not all of the word).
'overwhelmed by' means one lot of letters goes inside another (inserted letters get absorbed or overwhelmed).
'spanish team' becomes 'Real' (Real Madrid).
'city' with its last letter taken off is 'cit'.
'cit' put within 'real' is 'RECITAL'.
(Other definitions for recital that I've seen before include "Verbal account" , "Narration" , "Solo music performance" , "Telling" , "Concert performed by a solo musician" .)