Sudden eruption - and, reportedly, what might stifle it? (7)

I believe the answer is:

atishoo

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

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

(Other definitions for atishoo that I've seen before include "report of involuntary escape from trap?" , "hay-fever sufferer may interject this" , "25 sound" , "Sound of explosion" , "Sound of a sneeze" .)

I've seen this clue in The Telegraph.

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