Just like neon, argyle compression socks and the phrase "beast mode,” WOD, workout of the day, originally started with CrossFit and has since spread to the greater fitness population. A WOD (pronounced "wad") is simply a list of the exercises you're supposed to do that day. Gyms that use WODs generally put up a new one every 24 hours so you get concise instructions and a lot of training variety. But if you don't like it, just don't get your panties in a WOD. (Couldn’t resist.)
Another one you can expect to hear in a CrossFit box: AFAP, as fast as possible. The instructor gives you a certain number of reps to do for each exercise, and your goal is to finish quickly.