Particles of cut wood (7)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
sawdust
(Other definitions for sawdust that I've seen before include "Powdered wood" , "Powdery fragments from cut timber" , "Powdery substance from cut wood" , "Powdery fragments of wood" , "Fine wood shavings" .)