Having courage, nevertheless clears out (4)

I believe the answer is:

guts

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'out' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.

I can't explain the rest of the clue.

Can you help me to learn more?

(Other definitions for guts that I've seen before include "Eat greedily" , "backbone" , "Intestinal courage?" , "Inside - bottle!" , "Pluck -- intestines" .)

I've seen this clue in the Evening Standard.

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