Inert - yet changing time without end (8)

I believe the answer is:

eternity

'time without end' is the definition.

'inert yet changing' is the wordplay.
'changing' indicates anagramming the letters.
'inert'+'yet'='inertyet'
'inertyet' with letters rearranged gives 'ETERNITY'.

(Other definitions for eternity that I've seen before include "Sort of ring" , "Wolfgang Amadeus -" , "Jean-Paul --, French author" , "Unending time" , "Evermore" .)

I've seen this clue in The Telegraph.

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