Half a mile west, nominally (3)

I believe the answer is:

lew

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'half a mile west nominally' is the definition.
I can't judge whether this definition defines the answer.

'half a mile west' is the wordplay.
'half a' suggests halving the letters.
'west' becomes 'W' (abbreviation).
'mile' cut in half is 'le'.
'le'+'w'='LEW'

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(Another definition for lew that I've seen is " Not overheated".)

I've seen this clue in the Evening Standard.

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