America neologism - slam

Traditionally, we used "slam" as slamming the door or slamming the book down on the desk. Now it's used in other ways, but keeps its aggressive feel. First there was slam dancing, in which dancers intentionally bumped into each other. You might slam someone if you say something really harsh to them. There are poetry slams, which are really competitions with certain rules. Was the word slam chosen because poetry was considered, perhaps, a wimpy pursuit, while a "poetry slam" sounds macho and physical? -- though, as far as I can tell, it's neither. I also use it as meaning "overwhelmed with work," as in, "I'm sorry to bother you with this. I know you must be slammed with that meeting coming up." I've been afraid to use it in New Zealand, because it might mean something dirty. (Etymology uncertain, probably Scandinavian, akin to Old Norse, slambra, to strike at.)