Pole's prosperous period (4)

I believe the answer is:

boom

I believe this is a double definition.

'pole's' is the first definition.
(boom is a kind of pole)

'prosperous period' is the second definition.
(I've seen this before)

(Other definitions for boom that I've seen before include "Harbour barrier" , "Resonant sound, like artillery" , "Period of prosperity needed" , "Cry of the bittern" , "Period of prosperity - explosive sound - sailing boat's spar" .)

I've seen this clue in The Telegraph.

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