Melodious South Pacific (7)

I believe the answer is:

sirenic

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'melodious' is the definition.
Both the definition and answer are adjectives.
Maybe there's a link between them I don't understand?

'south pacific' is the wordplay.
'south' becomes 'S' (abbreviation).
'pacific' becomes 'irenic' (synonyms).
's'+'irenic'='SIRENIC'

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I've seen this clue in The Times.

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