Sups second after embracing maiden in 'Twilight' (7)
I believe the answer is:
dimness
'twilight' is the definition.
(thesaurus)
'sups second after embracing maiden' is the wordplay.
'sups' becomes 'dines' ('dine' can be a synonym of 'sup').
'second' becomes 's' (common abbreviation).
'after' is a charade indicator (letters next to each other).
'embracing' indicates putting letters inside.
'maiden' becomes 'm' (cricket abbreviation).
'dines'+'s'='diness'
'diness' going around 'm' is 'DIMNESS'.
'in' acts as a link.
(Other definitions for dimness that I've seen before include "That's not very clever" , "Quality of dull light" , "Dark" , "Shortage of light; weakness of intellect" , "exhibiting stupidity" .)