Gesture of respect for South African instrument (6)
I believe the answer is:
salute
'gesture of respect' is the definition.
(I've seen this before)
'south african instrument' is the wordplay.
'south african' becomes 'SA' (abbreviation).
'instrument' becomes 'lute' (lute is a kind of instrument).
'sa'+'lute'='SALUTE'
'for' is the link.
(Other definitions for salute that I've seen before include "Kind of welcome" , "Ceremonial firing of guns" , "Greet in military style" , "Greet with a sign" , "A greeting, often military" .)