African's vote — I'm surprised about it (5)
I believe the answer is:
xhosa
'african's' is the definition.
'vote i'm surprised about it' is the wordplay.
'vote' becomes 'x' (how votes are marked).
'i'm surprised' becomes 'oh' (expression of surprise).
'about' is a reversal indicator.
'it' becomes 'sa' (old-fashioned abbreviation for sex appeal).
'oh' backwards is 'ho'.
'x'+'ho'+'sa'='XHOSA'
(Other definitions for xhosa that I've seen before include "Tribesman" , "Cattle-rearer in South Africa" , "South African cattle-rearing people" , "Member of a Bantu-speaking tribe" , "Clicking tongue" .)