Crossword Genius

Tertiary function of some insurance (5,5)

Ross

I believe the answer is:

third party

'some insurance' is the definition.
(I've seen this before)

'tertiary function' is the wordplay.
'tertiary' becomes 'third' (synonyms).
'function' becomes 'party' (function can mean a social event).
'third'+'party'='THIRD-PARTY'

'of' acts as a link.

(Other definitions for third party that I've seen before include "Liberal Democrats?" , "Another (uninvolved) person" , "Person not directly involved" , "someone injured by driver?" , "Liberals once?" .)

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