Worked out old Eric wandered London area with daughter (9)
I believe the answer is:
exercised
'worked out' is the definition.
('exercise' can be a synonym of 'work out')
'old eric wandered london area with daughter' is the wordplay.
'old' becomes 'ex' (prefix meaning former or onetime).
'wandered' indicates anagramming the letters.
'london area' becomes 'SE' (abbreviation for South East).
'with' means one lot of letters go next to another.
'daughter' becomes 'd' (genealogical abbreviation).
'eric' is an anagram of 'erci'.
'ex'+'erci'+'se'+'d'='EXERCISED'
(Other definitions for exercised that I've seen before include "Kept fit" , "Practised" , "worried" , "Worked out" .)