Relative keels over unfortunately, going back to take a bow (6)
I believe the answer is:
salaam
'bow' is the definition.
(salaam is a kind of bow)
'relative keels over unfortunately going back to take a' is the wordplay.
'relative keels over' becomes 'm' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'unfortunately' becomes 'alas' (I've seen this before).
'going back' is a reversal indicator.
'to take' is an insertion indicator.
'm'+'alas'='malas'
'malas' backwards is 'salam'.
'salam' enclosing 'a' is 'SALAAM'.
Can you help me to learn more?
(Other definitions for salaam that I've seen before include "Peaceful greeting" , "Oriental greeting or homage" , "Muslim greeting signifying peace" , "Greetings" , "An Oriental greeting meaning peace" .)