Pass middle of week covering circuits (6)
I believe the answer is:
elapse
'pass' is the definition.
(synonyms)
'middle of week covering circuits' is the wordplay.
'middle of' says to take the centre.
'covering' indicates putting letters inside.
'circuits' becomes 'laps' ('lap' can be a synonym of 'circuit').
The middle letters of 'week' are 'ee'.
'ee' enclosing 'laps' is 'ELAPSE'.
(Other definitions for elapse that I've seen before include "Go past" , "'Pass by, as time (6)'" , "Passing" , "Glide by" , "run by" .)