Submissive nature of nemeses working over the weekend (8)
I believe the answer is:
meekness
'submissive nature' is the definition.
(I've seen this before)
'nemeses working over the weekend' is the wordplay.
'working' is an anagram indicator.
'over' is an insertion indicator.
'the weekend' becomes 'k' (I've seen this in other clues).
'nemeses' is an anagram of 'meeness'.
'meeness' enclosing 'k' is 'MEEKNESS'.
'of' acts as a link.
(Other definitions for meekness that I've seen before include "Submissive quality" , "Submissive nature" , "Deference" , "Formally inform" , "Modesty, humility" .)