Sonder n. the realization that each random passerby is living a life as vivid and complex as your own—populated with their own ambitions, friends, routines, worries and inherited craziness—an epic story that continues invisibly around you like an anthill sprawling deep underground, with elaborate passageways to thousands of other lives that you’ll never know existed, in which you might appear only once, as an extra sipping coffee in the background, as a blur of traffic passing on the highway, as a lighted window at dusk. – John Koenig, The Dictionary of Obscure Sorrows
That definition didn’t exist until 2012 when John Koenig created it for The Dictionary of Obscure Sorrows.
Before then, sonder was used to describe a class of small racing yachts.
While you may never use sonder in a sentence, it still stands as an example of how our language isn’t static.
Language is evolving.
New words are created all of the time and the definitions of the words we use today may not be how we use those words tomorrow.
Oxford University claims on their website that they add “several thousand words, including whole new entries and new senses of existing words” every year to the Oxford English Dictionary alone. 1
Change is inevitable.
As we change, our language changes too.