Have second thoughts about condition covering European disadvantages (10)
I believe the answer is:
reconsider
'have second thoughts' is the definition.
(thesaurus)
'condition covering european disadvantages' is the wordplay.
'condition' becomes 'rider' (I've seen this before).
'covering' indicates putting letters inside.
'european' becomes 'e' (abbreviation e.g. EU).
'disadvantages' becomes 'cons' (as in pros and cons).
'e'+'cons'='econs'
'rider' going around 'econs' is 'RECONSIDER'.
'about' is the link.
(Other definitions for reconsider that I've seen before include "Nice orders ( anag.)" , "Think again" , "Have second thoughts" , "Ponder further" .)