Flexible donation to charity (6)
I believe the answer is:
giving
I believe this is a triple definition!
'flexible' is the first definition.
(thesaurus)
'donation' is the second definition.
(thesaurus)
'to' is a link.
'charity' is the third definition.
(thesaurus)
(Other definitions for giving that I've seen before include "'Friday's child is loving and . . . . . .'" , "Handing over" , "Donating" , "Yielding; presenting" , "Granting" .)