Public is forbidden to charge (7)
I believe the answer is:
outward
'public' is the definition.
(thesaurus)
'forbidden to charge' is the wordplay.
'forbidden' becomes 'out' (synonyms).
'to charge' becomes 'ward' (both can mean a child in one's care).
'out'+'ward'='OUTWARD'
'is' is the link.
(Other definitions for outward that I've seen before include "Draw out (anag.)" , "Young person thus bound" , "(In the direction of the) exterior" , "Away from port" , "Away from centre" .)