Alex reminded me a of a few I've used in conversation, confirmed with the 4 writers I had lunch with today as widespread enough to include here. Also, another very specific term which is so elegant, it cries out for further use.
"a couplet": Two lines of dialogue -- one character speaks, another responds. Call and response, setup/punch, question/answer. Considered the basic molecule of script dialogue.
"first blurt": the very first pitch on a joke, and it makes everybody in the room laugh. You then spend 15 minutes trying to beat that joke, only to realize that writer's first instinctive joke was the best. When in doubt, first blurt wins. You can call "first blurt" in order to avoid --
"a joke spiral": the room's pitching on a joke, and no, that's not it, and pitching and pitching and now there's now way you'll come up with something funny and now it's a half-hour later on this one line and none of you feel funny and your energy's -- PULL UP, PULL UP IN THE NAME OF GOD before you spiral into the ground with one wing on fire!
"sock barrel": a collection of roughly identical jokes all about the same thing. Pick one, cut the rest.
"hang a lantern on it": Instead of trying to hide a script/credibility problem, address it in full measure, so it can be dealt with and discarded. "How does she break into the base?" "Hang a lantern on it, how tough it is to get the codes, but that makes her twice as cool for pulling it off." This is often a bit of sleight-of-hand, but hell, you're probably using it to address some --
"fridge logic": a logic problem in the script that the average viewer would only ask themselves about, say, an hour later when they're at the fridge getting a snack during commercials. TV is a very tight little medium time-wise, with an enormous amount of hand-waving to begin with. Often a logic problem that seems to smack you in the face because you've had the time to read the script, reread it, give notes, break it down, etc. is going to fly by your average -- and hopefully emotionally engaged -- viewer.
"Well, how'd she get from Dallas to Houston."
"Could she make the drive to the airport in time?"
"That's fridge logic."
Note that you're not trying to be lazy here -- you're just dealing with the fact that every line of exposition is a line that isn't active or particularly interesting, and you only get so many of those in 44 minutes before your show is now boring. Logically flawless, but boring.
"backstory": Information of absolutely no interest to an audience. But, it gives executives something to talk to writers about. (apologies, I believe, to Mamet)
"cheadle": as a verb. When a character laughs along with othe characters, then does a big physical head turn away from them and simultaneously his face reveals his inner rage/anguish/dismay.
From the Rat Pack movie, where Don Cheadle plays Sammy Davis Jr. Sammy's going along with this racist sketch at the Dunes, everyone's having a great time, big group laugh -- then Cheadle turns and his face falls, revealing (to the audience) Sammy's inner torment.
"The Scoutmasters laugh. Kevin cheadles. Making excuses, he exits."
Oh, and there's been some confusion, so:
"day player": A character with speaking lines crucial to this week's story, but not a regular. More than an extra, less than a guest star. They chatty guy who runs the dry cleaners when our hero goes to get a suit, the surly (but not-big-name) murderer on this week's CSI, the girl your guy is trying to pick up at the bar, most of the "other" castaways on LOST ... so named because they are paid a day-rate, not by the episode. This term leads to two others.
"day player theater": When a day player over-acts or otherwise tries to make the most of his brief moment in the sun. Welcome ... to Day Player Theater.
"sucking on the day player crack pipe": Over-writing a day player's role, until they have all the best lines and the focus of the scene. Almost always a sitcom situation.
This comes about because, well, TV's a frikkin' grind. Assume you're no farther than even halfway through the second season of a show. Wow, that's still pretty early, right?
35 episodes. That's THIRTY-FIVE STORIES about these same characters, and you've written oh 4-8 scens for each character permutation in the show, PLUS you can't significantly arc or change the characters (this is changing, but slowly). You know every trick, every rhythm of the actors you now work with. You know the lines they can hit, the jokes they don't know how to do, you know their parameters.
Now, along comes the day player. A new character, who you can do ANYTHING with, can have any backstory, their actions have no permanent repercussions for the show. The actor himself has all these neat new little rhythms, they're happy to get the job so they really sell the lines, it's all fresh and shiny, and if the person is actually GOOD, well then, all bets are off. It's FUN to write for a good day player, and you can write the big funny for them, they're there to service the plot and comedy, not the other way around, you're pitching jokes and situations you've never tried before and you're all laughing and when's the last time you all LAUGHED so hard in the writer's room you write them bigger and bigger, and you just can't stop --
You're sucking on the day player crack pipe. Put it down, and step away. Otherwise, you will have your star standing there with his thumb up his ass while the day player gets alllll the laughs. And that is not a happy day for anyone.