Start, if going wrong, initially (2,5)
I believe the answer is:
at first
'initially' is the definition.
(synonyms)
'start if going wrong' is the wordplay.
'going wrong' is an anagram indicator.
'start'+'if'='startif'
'startif' anagrammed gives 'AT FIRST'.
(Other definitions for at first that I've seen before include "In the beginning, initially" , "Originally" , "In the beginning, to start with" , "To begin with" .)