Reduce the work force with enthusiasm (4)
I believe the answer is:
fire
'enthusiasm' is the definition.
(I've seen this in another clue)
'reduce the work force' is the wordplay.
'reduce the work' becomes 'fir' (I can't justify this - if you can you should believe this answer much more).
'force' becomes 'e' (E is the symbol of electromotive force).
'fir'+'e'='FIRE'
'with' acts as a link.
Can you help me to learn more?
(Other definitions for fire that I've seen before include "There's no smoke without it" , "Shoot; sack" , "Manually operated device for dealing with flames" , "Trigger" , "Inspire" .)