Resort everyone rejected — Northern failure? No (9)
I believe the answer is:
llandudno
'resort' is the definition.
(I've seen this before)
'everyone rejected northern failure? no' is the wordplay.
'everyone' becomes 'all' (I've seen this before).
'rejected' shows that the letters should be reversed in order.
'northern' becomes 'n' (abbreviation e.g. N. Ireland).
'failure?' becomes 'dud' (dud is a kind of failure).
'all' in reverse letter order is 'lla'.
'lla'+'n'+'dud'+'no'='LLANDUDNO'
(Other definitions for llandudno that I've seen before include "Resort of N. Wales" , "holiday destination" , "Welsh coastal resort" , "Welsh seaside town" , "Welsh seaside resort" .)