Indicate one's been appalled lately? (4,2,4,5)

I believe the answer is:

turn in ones grave

'been appalled lately?' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'indicate one's' is the wordplay.
I cannot quite see how this works, but
'one's' could be 'ones' and 'ones' is located in the answer.
This explanation may well be incorrect...

(Another definition for turn in ones grave that I've seen is " react, although late".)

I've seen this clue in The Times.

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