Down-to-earth workman (4,8)

I believe the answer is:

farm labourer

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'down-to-earth workman' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'to-earth workman' is the wordplay.
'to-earth' becomes 'farm' (I am not sure about this - if you are sure you should believe this answer much more).
'workman' becomes 'labourer' (labourer is a kind of workman).
'farm'+'labourer'='FARM-LABOURER'

Can you help me to learn more?

I've seen this clue in The Irish News, The Guardian and The Globe and Mail.

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