Green professed cash primarily is for National Saving (10)
I believe the answer is:
economical
'saving' is the definition.
(I've seen this before)
'green professed cash primarily is for national' is the wordplay.
I cannot quite understand how this works, but
'green' could be 'eco' (abbreviation for ecological) and 'eco' is located in the answer.
'cash' could be 'l' (The pound sterling symbol is an elaborate L) and 'l' is located in the answer.
'national' could be 'n' (abbreviation listed in Chambers) and 'n' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for economical that I've seen before include "Cheap" , "Thrifty" , "Using little" , "Careful" , "Frugal" .)