Mother's returned a kitchen utensil - it's junk (6)
I believe the answer is:
sampan
'it's junk' is the definition.
(thesaurus)
'mother's returned a kitchen utensil' is the wordplay.
'mother's' becomes 'ma's' (ma can mean mother).
'returned' is a reversal indicator.
'a kitchen utensil' becomes 'pan' (I've seen this in another clue).
'mas' reversed gives 'sam'.
'sam'+'pan'='SAMPAN'
(Other definitions for sampan that I've seen before include "Far Eastern boat" , "Small Asian rowing boat" , "Asian skiff" , "East Asian boat" , "oriental vessel" .)