Courage needed by chickens? (4)

I believe the answer is:

grit

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'courage' is the definition.
(I've seen this before)

I don't understand the remainder of the clue.

(Other definitions for grit that I've seen before include "Small hard particles - courage" , "Gravelly courage" , "Fragments to sprinkle on roads" , "Jock's enormous" , "Courage, small stones" .)

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

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