Crossword Genius

While original a sermon’s interminable (2,4,2,4,3)

Ross

I believe the answer is:

as long as ones arm

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'interminable' is the definition.
I know nothing about this answer so I cannot judge whether this works.

'while original a sermon's' is the wordplay.
'while' becomes 'as long as' (I've seen this in another clue).
'original' indicates anagramming the letters.
'a'+'sermon'='asermon'
'asermon' with letters rearranged gives 'onesarm'.
'aslongas'+'onesarm'='AS LONG AS ONES ARM'

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