Standing on set with heart of steel (6)
I believe the answer is:
repute
'standing' is the definition.
(repute is a kind of standing)
'on set with heart of steel' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'set with' becomes 'put' (synonyms. I am not sure about the 'with' bit.).
'heart of' indicates the central letters.
The central letter of 'steel' is 'e'.
're'+'put'+'e'='REPUTE'
Can you help me to learn more?
(Other definitions for repute that I've seen before include "Fame, renown" , "State of high esteem" , "Generally held opinion" , "Public estimation" , "Public standing" .)