Guess teatime's off? (8)

I believe the answer is:

estimate

'guess' is the definition.
(I know that guess can be written as estimate)

'teatime's off?' is the wordplay.
'off?' indicates anagramming the letters (I've seen 'off' mean this).
'teatimes' anagrammed gives 'ESTIMATE'.

(Other definitions for estimate that I've seen before include "Judge the approximate cost of" , "Believe" , "Reckon value" , "Make an educated guess" , "rough judgment" .)

I've seen this clue in The Everyman puzzle in The Observer.

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