Prepared, once more, for the day shift (5)
I believe the answer is:
ready
'prepared' is the definition.
(associated in meaning)
'once more for the day shift' is the wordplay.
'once more' becomes 're' (I've seen this in other clues).
'for' means one lot of letters go next to another.
'shift' is an anagram indicator.
'day' anagrammed gives 'ady'.
're'+'ady'='READY'
(Other definitions for ready that I've seen before include "Primed" , "At hand" , "Prepare < dough" , "Willing (to do something), prepare" , "Prepared, willing" .)