a term used when a science fiction writer "waves his hands" at reality and hard science for the sake of the plot. Refers to all unrealistic or impossible technology, such as faster-than-light travel, teleportation, artificial gravity, etc.
Handwavium is extensively used in movies, more so than in literature, due to the need to mass market movies to a scientifically ignorant public and because filming realistic space travel is relatively expensive.
Star Trek is fun, but it's loaded with handwavium.
Armageddon sucked for many reasons, one of which was overuse of handwavium.
Apollo 13 didn't have any handwavium tech, it was all historically accurate hardware.
To be "danbusted" means to be arrested for doing something that is not against any law, but which the cop thinks is unlawful or just makes stuff up as he goes along. Originated in the gun rights movement when Dan Moore, whose internet forum moniker is "Danbus", was repeatedly arrested for lawfully carrying a visible sidearm in Norfolk, Virginia in the mid-2000's and was proven in the rights. His story was posted on the nationwide gun rights site opencarry.org, and gave rise to the verb "to danbust" among gun owners.
Dude, I got danbusted when the cop stopped me for not wearing a bike helmet, even though there's no law says I gotta have one.