Unusually, Americano lacks nice smell (5)
I believe the answer is:
aroma
'smell' is the definition.
(synonyms)
'unusually americano lacks nice' is the wordplay.
'unusually' is an anagram indicator.
'lacks' is a deletion indicator.
'americano' with 'nice' taken out is 'amrao'.
'amrao' anagrammed gives 'AROMA'.
(Other definitions for aroma that I've seen before include "Subtle quality" , "Strong smell" , "Scent - fragrance" , "Distinctive scent" , "Savour" .)