Oh dear best laugh I've had all day! Australians generally only use rhyming slang when overseas or faced with a mob of english speakers from another country when they have to desperately dredge up any distinctiveness and parade it around the place, the more cryptic the better. It's very old school stuff.
Milhouse is a dweeby fellow from the Simpsons who when things finally went his way one episode declared, "everything's coming up milhouse!" I'm just using words invented this century to prove my point without banging on and frakking with your patience.
I think I confused people in the Voyager forum when I made reference to Neelix being on the 'intergalactic nonce jotter' Nonce = Pedophile Jotter = Register/notebook
I can see the confusion, Guy is a Kiwi and comes from a place with lots of sheep, I am a sheep-shagger (Welsh*). * when it suits me.
You've also go to remember that just because people speak the same language their can be subtle or not so subtle differences between them. A word such as deplane might be used say in North America whilst in say the UK and Commonwealth countries disembark would be used instead.
My point is that it's an unnecessary word. A word already exists to describe that concept - "disembark," as Macleod says. I'm all for new words to describe new concepts. Of course Chaucer didn't have a word for "internet," because he didn't need one. Likewise there's no need to create a new word to describe "disembark" when there's already a perfectly good word that serves the purpose. After seven years of living in the States, I have to say my impression wasn't that it was a dialectal difference, but rather ignorance of the fact that the word "disembark" exists at all. Likewise, usage of such non-words as "winningest" on Nascar commentary makes me want to stab a bitch. I never said they were identical - I know they're not. But what possible middle ground is there between the two that requires a whole new word to describe it? Either something is an educated calculation (thus an "estimate") or it's not (thus a "guess"). It's like when people say "more unique." Impossible! "Unique" is an absolute state, it is not subject to gradation. .
Well, you say that, but "embark" comes from Middle French "Embarquer", with Em- being from "En" meaning in, and "Barque" meaning ship. So you're actually saying you're boarding a ship, not an aircraft, when you embark. (Barque came from the Latin Barca, meaning ship.) Thus, dis-em-bark would mean to get off a ship. I can certainly see the point in having a specific alternative for aircraft. (Of course, it's also true that you "embark" on a journey - this is a broadening of the original meaning, and lends support to the thought that we don't need any such alternative, but some people just prefer to be specific about their mode of transport.)
Well the definition of disembark is Leave a ship, aircraft, or other vehicle. And you can make a case for an aircraft being a ship, it's just a ship which travels through air instead of say the water or space. But language evolve and change overtime, some languages at a faster pace than others.