The act of cutting short your gym workout because of prior commitments afterwards, only to find out that those plans have fallen through.
Eric totally jockblocked me the other day. I left the gym early to go meet him at the bar, but I got text saying he had to cancel as soon as I got there.
Jokeblocking, an act usually carried out by a jokeblocker, is the gesture of deliberately ruining someone's attempt to tell a joke or cause others to laugh, either by distraction or dismissal. Not to be mistaken for cockblocking
Danny: Hey, listen to this joke! "Knock, kno-"
George: Dude that was funny three fucking years ago.
Danny: Damn, stop jokeblocking me.