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Bird
not
up
for
courtship
dancing
(7)
Bird not up for courtship dancing (7)
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The definition is at the beginning of the clue.
How the clue works
Right, so Bird is your definition there, pointing to an ostrich. Now for the wordplay - start with "courtship", whip out the letters of "up" since it says "not up", leaving you with CORTSHI, and then "dancing" tells you to shuffle those letters about to land on OSTRICH.