Most employees have to stop (4)
I believe the answer is:
stem
'stop' is the definition.
(stem can mean to stop or interrupt)
'most employees have' is the wordplay.
'have' says the answer is hidden in the clue.
'STEM' is hidden within 'most employees'.
'to' acts as a link.
(Other definitions for stem that I've seen before include "Restrain the flow of" , "Main upright of a ship's bow" , "Axis" , "Stalk - check" , "Staunch (flow)" .)