The smallest space for pikes to swim (7)

I believe the answer is:

pokiest

I'm a little stuck... Click here to teach me more about this clue!

'the smallest space for pikes to swim' is the definition.
I can't judge whether this definition defines the answer.

'pikes to swim' is the wordplay.
'swim' is an anagram indicator.
'pikes'+'to'='pikesto'
'pikesto' anagrammed gives 'POKIEST'.

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I've seen this clue in the Irish Times and the Irish Times (Crosaire).

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