Most employees have to hold back (4)
I believe the answer is:
stem
'hold back' is the definition.
(I've seen this before)
'most employees have' is the wordplay.
'have' indicates a hidden word.
'STEM' is hidden in the letters of 'most employees'.
'to' is the link.
(Other definitions for stem that I've seen before include "section of pipe" , "Supporting structure" , "Halt flow" , "'Stalk, shank (4)'" , "Restrict - part of a plant" .)