Nervous of snakes? (5)

I believe the answer is:

windy

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'nervous' is the definition.
(I've seen this before)

I don't understand how the rest of the clue works.

(Other definitions for windy that I've seen before include "Gusty" , "Chicago, the _____ City" , "Frightened - not still" , "far from calm" , "The sort of weather" .)

I've seen this clue in The Telegraph.

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