Falling off Big Ben (6)

I believe the answer is:

ebbing

'falling' is the definition.
(thesaurus)

'off big ben' is the wordplay.
'off' indicates anagramming the letters.
'big'+'ben'='bigben'
'bigben' is an anagram of 'EBBING'.

(Other definitions for ebbing that I've seen before include "Declining" , "Receding like Big Ben" , "Going out like a tide" , "in decline?" , "Gradually growing less" .)

I've seen this clue in The Guardian and The Globe and Mail.

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