This cuts absence from work, reducing it by a third (6)
I believe the answer is:
sickle
This clue might be a double definition.
'this cuts absence from work reducing it' is the first definition.
The definition suggests a singular noun which matches the answer.
'a third' is the second definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'by' acts as a link.
Can you help me to learn more?
(Other definitions for sickle that I've seen before include "Corn-cutting tool" , "field-worker being a trimmer" , "Cutting farming tool" , "Farm implement" , "Harvesting implement" .)