Sneaky subordinate worker (9)
I believe the answer is:
underhand
'sneaky' is the definition.
('underhand' can be a synonym of 'sneaky')
'subordinate worker' is the wordplay.
'subordinate' becomes 'under' ('under' can be similar in meaning to 'subordinate').
'worker' becomes 'hand' (hand is a kind of worker**).
'under'+'hand'='UNDERHAND'
(Other definitions for underhand that I've seen before include "In a secret or dishonest way" , "Surreptitious" , "done deviously through cover" , "Unsporting" , "Reporting to worker" .)