Harvesting machine (6)
I believe the answer is:
reaper
'harvesting machine' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for reaper that I've seen before include "Wordsworth's was Solitary" , "Farmworker" , "One harvesting crop" , "One who cuts grain as harvest" , "One gathers" .)