The last word about German and Swiss origin of explorer (8)
I believe the answer is:
amundsen
'explorer' is the definition.
(I've seen this before)
'the last word about german and swiss origin' is the wordplay.
'the last word' becomes 'amen' (last word in a prayer).
'about' is an insertion indicator.
'german and' becomes 'und' ('and' in German).
'origin' indicates taking the first letters.
The initial letter of 'swiss' is 's'.
'und'+'s'='unds'
'amen' going around 'unds' is 'AMUNDSEN'.
'of' acts as a link.
(Other definitions for amundsen that I've seen before include "Norwegian polar explorer, d. 1928" , "Roald --, first to reach the South Pole" , "First man to reach South Pole" , "6 24 113 [SCAN-DIN-AVIAN] explorer" , "Roald -, Norwegian polar explorer" .)