Failing of Scandinavian nomads, by the sound of it (5)
I believe the answer is:
lapse
'failing' is the definition.
(a moral failing)
'scandinavian nomads by the sound of it' is the wordplay.
'scandinavian nomads' becomes 'lapps' (I've seen this in another clue).
'by the sound of it' shows a homophone (sound like).
'lapps' is a homophone of 'LAPSE'.
'of' acts as a link.
(Other definitions for lapse that I've seen before include "Sepal (anag)" , "Temporary failure of judgment or concentration" , "Slight error as caused by inattention" , "Retrogress" , "Error cause by weakness or inattention" .)