Tin with old-fashioned tobacco (5)
I believe the answer is:
snout
'tobacco' is the definition.
(I've seen this before)
'tin with old-fashioned' is the wordplay.
'tin' becomes 'sn' (Sn is the chemical symbol for tin).
'with' is a charade indicator (letters next to each other).
'old-fashioned' becomes 'out' (as opposed to 'in').
'sn'+'out'='SNOUT'
(Other definitions for snout that I've seen before include "Nose and mouth of a mammal" , "Nose, tobacco (colloq.)" , "Porker's hooter?" , "Projecting nasal area of animal" , "nose of pig" .)