German composer’s pal chasing small girl (8)
I believe the answer is:
schumann
'german composer's' is the definition.
(Robert Schumann)
'pal chasing small girl' is the wordplay.
'pal' becomes 'chum' (synonyms).
'chasing' means one lot of letters go next to another.
'small' becomes 's' (abbreviation - e.g. clothes size).
'girl' becomes 'ann' (woman's name).
'chum' after 's' is 'schum'.
'schum'+'ann'='SCHUMANN'
(Other definitions for schumann that I've seen before include "Robert -, nineteenth century German composer" , "Oddly, the German composer is Nan's chum" , "Robert --, German romantic composer" , "German barman" , "German composer, 1810-56" .)