Conciliatory gesture (5,6)
I believe the answer is:
olive branch
'conciliatory gesture' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for olive branch that I've seen before include "Emblem of peace" , "Symbol of peace" , "attempt at conciliation" , "One offered in peace" , "that will come to a 'sticky' end" .)