Philanthropic scientist in Brazil's capital during Christmas (5)
I believe the answer is:
nobel
'philanthropic scientist' is the definition.
(Alfred Nobel)
'brazil's capital during christmas' is the wordplay.
'capital' says to take the initial letters.
'during' means one lot of letters goes inside another.
'christmas' becomes 'Noel' (Noel can mean Christmas).
The first letter of 'brazils' is 'b'.
'b' put into 'noel' is 'NOBEL'.
'in' acts as a link.
(Other definitions for nobel that I've seen before include "he provided prizes" , "Swedish prize-giver" , "6 24 113 [SCAN-DIN-AVIAN] chemist" , "Dynamite inventor, Prize founder" , "-- Peace Prize" .)