Farmer with his own lunch (9)
I believe the answer is:
ploughman
'farmer' is the definition.
(I know that ploughman is a type of farmer)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for ploughman that I've seen before include "One with shares in Labour" , "Agricultural worker (having lunch?)" , "possibly, in the farm" , "His groundbreaking work" , "Tiller of soil" .)