Prevent collapses of the coast? (5)

I believe the answer is:

shore

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'coast?' is the definition.
(I know that coast can be written as shore)

I can't explain the rest of the clue.

(Other definitions for shore that I've seen before include "Land along the edge of sea or lake" , "Seafront" , "Land by water" , "Sailors might, given such leave" , "Coast" .)

I've seen this clue in the Evening Standard.

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