What a miller does is hard work (5)

I believe the answer is:

grind

This clue is a double definition.

'what a miller does' is the first definition.
(mill can mean to grind or crush)

'is hard work' is the second definition.
(I've seen this before)

(Other definitions for grind that I've seen before include "Wear down" , "To prepare coffee beans" , "Hard dull work" , "drudgery" , "Chore" .)

I've seen this clue in The Globe and Mail.

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