Shift the mud, etc., in buckets (6)
I believe the answer is:
dredge
'shift' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I can't see?
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for dredge that I've seen before include "Sprinkle flour" , "Scrape up material from sea bed" , "Scoop up mud and silt from harbour bottom" , "Remove material from a channel or riverbed" , "River-bed clearer" .)