Close to nadir in power cut, there’s indignation (7)
I believe the answer is:
outrage
'indignation' is the definition.
(synonyms)
'close to nadir in power cut' is the wordplay.
'close to' indicates one should take the final letters (the 'close' to the word).
'in' indicates putting letters inside.
'power cut' becomes 'outage' (an outage is a loss of power).
The last letter of 'nadir' is 'r'.
'r' going within 'outage' is 'OUTRAGE'.
'there's' is the link.
(Other definitions for outrage that I've seen before include "Intolerable or shocking act, to argue about" , "Deplorable insult" , "Shocking event" , "Scandal" , "Strong reaction of anger or indignation" .)