Cut back on iron? (8)
I believe the answer is:
decrease
I believe this clue is a double definition.
'cut back' is the first definition.
(I've seen this before)
'iron?' is the second definition.
(I've seen this in another clue)
'on' acts as a link.
(Other definitions for decrease that I've seen before include "Reduction" , "Abate, diminish" , "Turn down" , "Reduce, lessen" , "Contract" .)