Young family makes mess (6)
I believe the answer is:
litter
I believe this is a triple definition!
'young' is the first definition.
(thesaurus)
'family' is the second definition.
(I've seen this before)
'makes' acts as a link.
'mess' is the third definition.
(thesaurus)
(Other definitions for litter that I've seen before include "Not a neat" , "Chair or bed carrried on two poles" , "Young dogs, perhaps" , "Form of transport" , "Carelessly-dropped rubbish" .)