Duke ordering rash acts of bravery (7-2)
I believe the answer is:
derring-do
'acts of bravery' is the definition.
'derring do' can be an answer for 'bravery' (I've seen this before). I am not certain of the 'acts of' bit.
'duke ordering rash' is the wordplay.
'duke' becomes 'd' (abbreviation).
'rash' indicates an anagram (a reckless or careless ordering of the letters).
'ordering' anagrammed gives 'erringdo'.
'd'+'erringdo'='DERRING-DO'
Can you help me to learn more?
(Other definitions for derring-do that I've seen before include "Brave acts" , "Courageous action" , "Swashbuckling boldness" , "Literary word for heroic courage or action" , "heroic deeds" .)