Spending's first, reportedly, to show generosity (8)
I believe the answer is:
largesse
'generosity' is the definition.
(I've seen this before)
'spending's first reportedly to show' is the wordplay.
'spending's first' becomes 's' (lst letter of 'spending').
'reportedly' becomes 'e' (I've seen this in other clues).
'to' means one lot of letters go next to another (I've seen this in other clues).
'show' becomes 'larges' (I am not sure about this - if you are sure you should believe this answer much more).
's'+'e'='se'
'se' after 'larges' is 'LARGESSE'.
Can you help me to learn more?
(Other definitions for largesse that I've seen before include "Magnanimity, munificence" , "Magnanimous bestowal of gifts" , "Liberal gift" , "Generosity in bestowing gifts" , "Bounty, gift" .)