Tolerate noble punishment, relinquishing power (11)
I believe the answer is:
countenance
'tolerate' is the definition.
(thesaurus)
'noble punishment relinquishing power' is the wordplay.
'noble' becomes 'count' (count is a kind of noble).
'punishment' becomes 'penance' (penance is a kind of punishment).
'relinquishing' indicates named letters should be taken away.
'power' becomes 'p' (symbol in physics).
'penance' with 'p' removed is 'enance'.
'count'+'enance'='COUNTENANCE'
(Other definitions for countenance that I've seen before include "Visage; accept as possible" , "features" , "Favour" , "A person's face; admit as possible" , "Accept as possible; face" .)