Part of the day in which there's no glory (6)
I believe the answer is:
honour
'glory' is the definition.
(I've seen this before)
'part of the day in which there's no' is the wordplay.
'part of the day' becomes 'hour' ('hour' is part of 'day').
'in which there's' indicates putting letters inside.
'hour' placed around 'no' is 'HONOUR'.
(Other definitions for honour that I've seen before include "Be faithful to; glory" , "pay tribute to" , "Great respect, perhaps among thieves" , "Award conferred as a mark of respect" , "Good name" .)