Note from the boss (4)
I believe the answer is:
memo
'note from the boss' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for memo that I've seen before include "Reminder (abbr)" , "Office note" , "- Currie, Br. politician" , "A little something to be remembered" , "Businesslike message" .)