Crossword Genius

A stonefish unclasped curling iron in shock (8)

Ross

I believe the answer is:

astonish

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

I cannot understand how the remainder of the clue works.

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(Other definitions for astonish that I've seen before include "Startle" , "electrify" , "Stun" , "Floor" , "Confound" .)

I've seen this clue in the Sydney Morning Herald.
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