Great letter mentioned distribution of gifts (8)
I believe the answer is:
largesse
'gifts' is the definition.
(I've seen this in another clue)
'great letter mentioned distribution' is the wordplay.
I cannot really see how this works, but
'great' could be 'large' (similar in meaning) and 'large' is located in the answer.
'letter' could be 's' and 's' is found within the answer.
The remaining letters 'se' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'of' acts as a link.
Can you help me to learn more?
(Other definitions for largesse that I've seen before include "Money or gifts generously given" , "Generous alms" , "Generosity in gift-giving" , "Liberal gift" , "Magnanimity, munificence" .)