Write about European change (5)
I believe the answer is:
pence
'change' is the definition.
(as in small change coins)
'write about european' is the wordplay.
'write' becomes 'pen' (synonyms).
'about' becomes 'c' (abbreviation for circa).
'european' becomes 'E' (abbreviation e.g. EU).
'pen'+'c'+'e'='PENCE'
(Other definitions for pence that I've seen before include "Little coins" , "''... fumble in a greasy till/and add the halfpence to the ...'' (Yeats)" , "Small quantity of money" , "President's vice" , "Fractions of a pound" .)