Dreadful Australian orgy (10)

I believe the answer is:

saturnalia

'orgy' is the definition.
('saturnalia' can be a synonym of 'orgy')

'dreadful australian' is the wordplay.
'dreadful' is an anagram indicator.
'australian' anagrammed gives 'SATURNALIA'.

(Other definitions for saturnalia that I've seen before include "Wild Roman festival" , "wild party" , "Old festival" , "orgy" , "revels" .)

I've seen this clue in The Telegraph.

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