Ostentatious display with a siphon (6)

I believe the answer is:

splash

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'ostentatious display' is the definition.
(as in making a splash)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for splash that I've seen before include "Bright patch of colour; fall in drops" , "Water raised by blow" , "A Bigger --, Hockney painting" , "Fall in irregular drops" , "Excitement" .)

I've seen this clue in The Globe and Mail.

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