Level of nationwide greed (6)
I believe the answer is:
degree
'level' is the definition.
(I've seen this before)
'of nationwide greed' is the wordplay.
'of' indicates the answer is hidden within the clue.
'DEGREE' is hidden within 'nationwide greed'.
(Other definitions for degree that I've seen before include "Measure for angle and temperature" , "Angular unit; stage" , "Award given to a college graduate" , "Academic award - stage on a scale" , "Scholastic award for a grade on a scale" .)