blue button

== English == === Alternative forms === blue-button === Noun === blue button (plural blue buttons) A colony of hydrozoan polyps of the species Porpita porpita (UK, finance, historical) An unauthorized clerk in the stock exchange. Coordinate term: red button === References === blue button on Wikipedia.Wikipedia Porpita on Wikispecies.Wikispecies Category:Porpita on Wikimedia Commons.Wikimedia Commons