Drop journalist into protest (9)
I believe the answer is:
reduction
'drop' is the definition.
(I've seen this before)
'journalist into protest' is the wordplay.
'journalist' becomes 'ed' (short for editor).
'into' is an insertion indicator.
'protest' becomes 'ruction' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'ed' inserted within 'ruction' is 'REDUCTION'.
Can you help me to learn more?
(Other definitions for reduction that I've seen before include "thickened sauce?" , "Drop in price" , "Introduce (anag) - decrease" , "cutback!" , "cut" .)