Object of night shift (5)
I believe the answer is:
thing
'object' is the definition.
(thing is a kind of object)
'night shift' is the wordplay.
'shift' is an anagram indicator.
'night' anagrammed gives 'THING'.
'of' is the link.
(Other definitions for thing that I've seen before include "Night (anag)" , "Article" , "Inanimate object" , "Individual unit" , "Affair - matter" .)