Ordering caviare demonstrates greed (7)
I believe the answer is:
avarice
'greed' is the definition.
(synonyms)
'ordering caviare' is the wordplay.
'ordering' is an anagram indicator.
'caviare' anagrammed gives 'AVARICE'.
'demonstrates' is the link.
(Other definitions for avarice that I've seen before include "A deadly sin" , "Insatiable desire for wealth" , "Wanting to be rich" , "Greed for gain" , "excessive desire for wealth" .)