Employee seen in fear, nervous (6)
I believe the answer is:
earner
'employee' is the definition.
(earner is a kind of employee)
'in fear nervous' is the wordplay.
'in' indicates the answer is hidden within the clue.
'EARNER' is hidden within 'fear nervous'.
'seen' is the link.
(Other definitions for earner that I've seen before include "Cash job" , "Money-making activity" , "Profitable enterprise" , "Lucrative activity" , "Something that makes a profit" .)