A lack of banknotes, say, circulating currently (8)
I believe the answer is:
nowadays
'currently' is the definition.
(I've seen this before)
'a lack of banknotes say circulating' is the wordplay.
'a lack of' becomes 'no' (eg no bread means a lack of bread).
'banknotes' becomes 'wad' (I can't justify this - if you can you should believe this answer much more).
'circulating' indicates anagramming the letters.
'say' anagrammed gives 'ays'.
'no'+'wad'+'ays'='NOWADAYS'
Can you help me to learn more?
(Other definitions for nowadays that I've seen before include "In the 21st century" , "Gestures of respect" , "present times" , "in the current period?" , "Currently" .)