Mixed pairs do a race round the world (8)
I believe the answer is:
diaspora
'race round the world' is the definition.
(I've seen this before)
'mixed pairs do a' is the wordplay.
'mixed' indicates an anagram.
'pairs'+'do'='pairsdo'
'pairsdo' with letters rearranged gives 'diaspor'.
'diaspor'+'a'='DIASPORA'
(Other definitions for diaspora that I've seen before include "Dispersion of a people from their homeland" , "The scattering of a people from the same home country" , "People scattered" , "Migrants" , "Scattering of the Jews from Israel" .)