Work on a spread (5)

I believe the answer is:

doona

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'spread' is the definition.
I don't know anything about this answer so I cannot judge whether this works.

'work on a' is the wordplay.
'work' becomes 'do work' (synonyms).
'do'+'on'+'a'='DOONA'

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

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