Back in Dolgellau, Susannah’s no different from normal (2,5)
I believe the answer is:
as usual
'no different from normal' is the definition.
'back in dolgellau susannah's' is the wordplay.
'back' shows that the letters should be reversed in order.
'in' indicates the answer is hidden within the clue.
'laususa' can be found hidden inside 'dolgellau susannah'.
'laususa' in reverse letter order is 'AS USUAL'.
(Other definitions for as usual that I've seen before include "'In the normal way (2,5)'" , "In line with practice" , "In the customary way" , "Customarily" , "In the normal way, habitually" .)