SWIFT is defined as an acronym for the “Society for Worldwide Interbank Financial Telecommunication” a Brussels-based financial telecommunications network that connects 8,500 member banks throughout the world.n a swift manner. 1  a cylinder in a carding machine. 2  an expanding reel used to hold skeins of silk, etc. that are being wound off. 3  any of a large family (Apodidae, order Apodiformes) of aerial-feeding, insectivorous, swift-flying, swallowlike birds with long, stiff wings and a small, weak bill, as the chimney swift.