Nose not opposed to unpleasant smell is following Staff Corps (9)
I believe the answer is:
proboscis
'nose not' is the definition.
'proboscis' can be an answer for 'nose' (I've seen this before). I am unsure of the 'not' bit.
'opposed to unpleasant smell is following staff corps' is the wordplay.
I cannot really see how this works, but
'smell' could be 'bo' (abbreviation for Body Odour) and 'bo' is present in the answer.
'is' is present in the answer.
an anagram of 'corps' is 'prosc' which is present in the remaining letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for proboscis that I've seen before include "Long nose" , "Elephantine nose" , "Snout" , "MONKEY" , "The human nose" .)