Nose? A sort of nose, almost entirely (5)
I believe the answer is:
aroma
'nose?' is the definition.
(I've seen this in another clue)
'a sort of nose almost entirely' is the wordplay.
'sort of nose' becomes 'Roman'.
'almost entirely' means to remove the last letter.
'roman' with its last letter removed is 'roma'.
'a'+'roma'='AROMA'
(Other definitions for aroma that I've seen before include "Stink" , "Subtle quality" , "Agreeable odour" , "Scent - fragrance" , "Pervasive quality" .)