Risk failure, having excelled in America in courage (4,4,4)
I believe the answer is:
push ones luck
'courage' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'risk failure having excelled in america' is the wordplay.
'risk failure' becomes 'pluck' (I can't justify this - if you can you should give a lot more credence to this answer).
'having' means one lot of letters goes inside another.
'excelled' becomes 'shone' (shine can mean to excel or do well).
'in' indicates putting letters inside.
'america' becomes 'US' (United States).
'shone' going within 'us' is 'ushones'.
'pluck' enclosing 'ushones' is 'PUSH ONES LUCK'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for push ones luck that I've seen before include "Press advantage to brink of failure" , "Take a risk, hoping still to be fortunate" .)