It's foolish to be very close to the bat (5)

I believe the answer is:

silly

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'it's foolish' is the definition.
(similar in meaning)

I don't understand the rest of the clue.

(Other definitions for silly that I've seen before include "Idiotic" , "Ridiculous, frivolous" , "Inane; very close (fielder)" , "Potty or barmy" , "near the batsman" .)

I've seen this clue in the Evening Standard.

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