Approved play area old firm finally repaired (11)
I believe the answer is:
recommended
'approved' is the definition.
(thesaurus)
'play area old firm finally repaired' is the wordplay.
'play area' becomes 'rec' (short for recreation ground).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'finally' suggests the final letters.
'repaired' becomes 'mended' ('mend' can be a synonym of 'repair').
The final letter of 'firm' is 'm'.
'rec'+'o'+'m'+'mended'='RECOMMENDED'
(Other definitions for recommended that I've seen before include "Advised (to do something)" , "Advised (a course of action)" , "Advocated" .)