An exclamation of astonishment, originally used in "The X-Files" Episode 19 of Season 7, approximately 18 minutes into the episode.
Tech guy: "Who made this?"
Scully: "We're not sure. Either a forger by the name of Micah Hoffman, or, uh, someone else in the vicinity of Jesus Christ."
Tech guy scoffs, looking incredulously at Scully: "What?"
Scully looks at him frankly, affirming that it might be true.
Tech guy, reverently: "Buzzinga."
While our lifespan is the number of years we will live, our healthspan is the number of healthy years we will have and our sexspan is is the number of years we will continue to be healthy enough to continue having an active sex life.
A lighthearted reaction upon receiving disappointing news of some sort. Usually something that isn't a particularly a big deal, esp. when it primarily affects someone else - sort of a mild schadenfreude. Sometimes doubled or tripled, and possibly said in a sing-songy voice for added comedic effect to imitate a muted trumpet, which is how the meme originated.