Abuse was rained on new girl at first (5)
I believe the answer is:
wrong
'abuse' is the definition.
(thesaurus)
'was rained on new girl at first' is the wordplay.
'at first' indicates taking the first letters.
The first letters of 'was rained on new girl' is 'WRONG'.
(Other definitions for wrong that I've seen before include "Inappropriate" , "Erronious" , "Erroneous" , "Injury - incorrect" , "Unjust - incorrect" .)