Words can also fall out of fashion. Photo / AP
A war of words is taking place and victory will be measured not in cheers, but in silence.
It's a battle fought as we choose our words and the casualties are what we forget.
Every year, new words are added to the dictionary - most recently "democracy sausage".
But what about the words that have passed their sell-by date?
When was the last time you talked about a "fortnight" rather than "two weeks"?
If you get married will you refer to your "fiancé" or your "partner"? And has anyone uttered the word "bonzer" in the past decade?
These words - and more besides - are on diction death row. They may soon become extinct.
Under-used, unloved and unwanted, linguists are waiting for them to meet their high noon, victims of changing fashions, technological obscurity and globalisation.
"Words can drop out of the dictionary," Victoria Morgan, senior editor of the Macquarie Dictionary told news.com.au.
"While we tend not to drop as many words as we add there is definitely a limit. The current edition weighs a good 5kg so there is a restriction of space in the physical dictionary."
Professor of linguistics at Sydney University, Nick Enfield, said there was a similarity between words and clothes.
"Words, like fashions, come in and out.
"Like flared pants, some words can attract lots of interest at certain times but can get dated really fast.
"Words die when out when they are no longer at the heart of our language," he said.
There are three main reasons why the terms we use change. Words become obsolete because the thing they refer to no longer exists; fashionable terms can become passé and words can be superseded by other ways of speaking.
"The reason language changes is because each generation has to learn a language for themselves and what they do is construct a slightly changed version.
"Essentially you don't pass on a language, you rebuild a language, so what's surprising is that language remains as stable as it does and doesn't change more."
A British survey from 2011 found words such as "laggard", "rambunctious" and "felicitations" had seen a dramatic drop off in use.
So what words will we soon say sayonara to?
"Talk to people over 30 and they will have a clear appreciation of what a compact disc is. But I don't know if a 17-year-old would know what a CD, cassette or a floppy disk was," said Prof Enfield.
"Getting rid of an object or process is a sure fire way to get rid of a word.
"They're transient terms for a transient phenomenon."
He said "laptop" could also be endangered because of the popularity of tablets and "iPhone" could eventually go the way of the dodo as the word had failed to become a noun in the same way Google had.
Slang terms are always close to the chopping block because they are originally used between members of sub cultures, said Enfield.
Once everyone starts using them they stop being, well, cool.
"A family of words that changes very quickly are similes. Words like good or bad have very alternative terms like 'sick', 'cool' or 'groovy'," he said.
"Groovy is not dead but it's not in very good shape because of all that 60s hippie stuff and those embarrassing stereotypes.
"If someone says 'that's really groovy', it doesn't sound right, whereas cool has survived unscathed perhaps because it's short and simple.
"Taylor Swift singing 'this sick beat' has seen that term become popular but I'm pretty sure it won't last long."
Morgan said "bonza" wasn't having a bonza time either. "It's dated and there's 1000 other terms now being used."
We know what it means, but we don't like it.
A 2015 online survey by website BuzzFeed found a third of people found the term "awkward" and preferred "partner" instead.
Writing in the New York Times, Hayley Phelan explained why fiancé was now a fail.
"It sounds silly, feels pompous and even precious. It's the verbal equivalent of wearing a monocle.
"During my engagement, I never managed to say the word without feeling, somehow, like a jerk."
Ironically, the ever expanding march of English across the globe seems to be putting this word in the bin.
"With globalisation lots of people using English are second language speakers and while there's lots of words for 'week' [in other languages] there are not many for two weeks," said Enfield.
"Second-language learners can affect the language over time as they introduce new ideas and habits.
"For a lot of people fortnight seems pointless. It's highly specific. Why do we have a word for two weeks and not three? And we don't we have fort days?"
Thrice is already there and twice could be about to join it in the great word waiting room in the sky, leaving once all alone.
It's not there yet. The Macquarie Dictionary officially classes thrice as "archaic", but twice still has some life. The signs aren't good, however. In ads, twice is increasingly being dumped for "two times".
"Noon is being overtaken by midday," said Prof Enfield. "It's a subtle change but noon seems so old fashioned".
Yet "afternoon" is as healthy as ever.
These terms aren't dying out but they are defining fewer things as more modern terms chip away at them.
"These words are becoming obsolete. Swimming baths as opposed to swimming pools and it's only the older generation who say they are going to a picture show as younger people say cinema," said Morgan.
Some of the definitions of adrift, such as meaning being absent without leave from the military, are little used.
Morgan said the Macquarie used a system of labels - such as "archaic", "obsolete" and "dated" - to mark words that were used less and less.
"If they are very rare they get dropped from the dictionary."
Firstly, a word on its last legs - often long-gone scientific terms - will disappear from the smaller dictionaries such as the Concise Macquarie, has space for 67,000 entries.
Many will get a stay of execution in the Complete dictionary, the seventh edition of which is published early next year, and which holds more than 122,000 words.
However, Morgan stressed that even in the concise dictionary there were still lots of words whose halcyon days have gone. "Thrice", for instance, still gets a look in.
And these days, words - however obscure - never die out completely. With Macquarie's online dictionary there'll always be a digital space for terms that haven't stood the test of time in print.
So, in the next fortnight, why not take your fiance to the pictures around noon to watch a bonza film. In fact, why not go twice and do your bit to give weary words a new lease of life.