Mason's tool (6)
I believe the answer is:
trowel
'mason's tool' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for trowel that I've seen before include "Potting tool" , "This makes plaster spread" , "Small gardening tool for lifting plants" , "Small tool for scooping or spreading" , "Hand tool for plasterers or gardeners" .)