Photocopier powder (5)
I believe the answer is:
toner
'photocopier powder' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for toner that I've seen before include "Black or coloured powder used in a printer" , "Chemical solution used to soften colours" , "Skin-cleansing lotion" , "Powder used in printers" , "Powdered pigment used in laser printers" .)