Inspired by the recent thread titled “Cis Women…” Outside of the transexual community, it’s safe to say that few people have heard this term.
Unless you’re a stickshift enthusiast, or know some, you’re probably not familiar with the term “slushbox” (an automatic transmission).
What other terms can people offer that are pretty much unknown except in certain sub-cultures. (And of course, what does it mean?)
In woodworking, a neanderthal is someone who only uses non-electric hand tools such as planes, handsaws, braces (hand drills), rasps, and the like.
I could converse with another soldier while barely using any actual English words and be perfectly understood. Army is pretty much it’s own language.
how do you mean the question?
a term that is not used elsewhere
a term that has a specific meaning unique to a subculture
Do you know what a THACO is?
If so, you probably used to play Role Playing games such as D&D.
Do you prefer a whisker biscuit or a drop away rest?
If so, you are probably an archer.
Many sailing terms:
Head knocker, etc…
This. I sometimes think soldiers purposely don’t want to be understood by the general public.
If you use “tk” to indicate missing material that will be added later, I’d guess you’d worked in publishing or journalism. Counter-intuitively, it stands for “to come.”
Lots of computer terms. PEBKAM, Three-finger salute, FSCK, RTFM.
“In the weeds” is a chef’s term I don’t think the general public is aware of. It means you’re behind.
“Frogging” is a knitter’s term. It’s when you take apart a project; you have to rip it, rip it. 
I know the term in the weeds. I have never been in the food service industry and didnt know its origin but I know what it means.
in radio it means receiving a weak signal.
Haha shows what I know!
When I worked in restaurants I heard that term used more by the waitstaff. Of course, It’s been a few years and I could be forgetting.
He is asking for examples of jargon.
Among Civil War reenactors, fair-weather reenactors/poseurs are “farbs.”
I think a lot of jargon is used to separate the insiders from the outsiders, whether it be the military or a group of golfers.
Yeah, RPG’s have their own subculture and vocabulary, some of which is shared with online gamers.
People who administer construction projects know RTFC (read the fucking contract).
In estimating, a ‘bust’ is when a bidder forgets to include important line item costs.
Outside of either of those contexts, I’ve always used/taken it to mean “into something difficult/sticky”
As in “I don’t want to get deep into the weeds on this but the quick answer to your question on religion is…”
If I heard a chef/radio operator use it in their contexts, I’d have been confused as hell 
In restaurant-speak, “in the weeds” just means “really, really busy”.