Start from the top end (4)

I believe the answer is:

open

'start' is the definition.
(I know that open is a more specific form of start)

'from the top end' is the wordplay.
'from' indicates a hidden word.
'OPEN' is hidden within 'top end'.

(Other definitions for open that I've seen before include "Widely known" , "Frank and unlocked" , "Allowing entry and exit" , "Not shut up or hidden" , "Not shut or secret" .)

I've seen this clue in the Evening Standard.

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