Many people have asked, "What does Swift stand for?". In truth it does not stand for anything. The "Swift" name is not an acronym. The observatory is actually named after a small, nimble bird, the same bird that appears in the Swift logo. The Swift observatory is built to be agile, quickly turning to point its instruments at gamma-ray bursts and relaying the burst locations to the ground within seconds, much like the Swift bird might grab up insects as it flies through the sky. Thus the Swift bird serves as a metaphor for the Swift observatory.
Science Question of the Week about the Swift mission name