Girl charges for errands (8)
I believe the answer is:
missions
'errands' is the definition.
The answer and definition can be both acts as well as being plural nouns.
Perhaps you can see an association between them that I can't see?
'girl charges' is the wordplay.
'girl' becomes 'miss' (term of address for an unmarried woman).
'charges' becomes 'ions' (I am not sure about this - if you are sure you should believe this answer much more).
'miss'+'ions'='MISSIONS'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for missions that I've seen before include "religious buildings - with 14a" , "Bombing raids" , "Journeys for scientific, military or religious purpose" .)