Wind up in Orange River (5)
I believe the answer is:
anger
'wind up' is the definition.
(wind up can mean to annoy or anger)
'in orange river' is the wordplay.
'in' indicates a hidden word.
'ANGER' can be found hidden inside 'orange river'.
(Other definitions for anger that I've seen before include "Strongly annoy" , "Hot displeasure; enrage" , "Spleen" , "Great annoyance" , "There's fury" .)