You might have come across this word recently, possibly tweeted by a dictionary or trivia account as a word of the day. It refers to the profound and sudden realisation that complete strangers have rich and complex inner lives.

It’s a popular word to share because it often elicits two reactions: Wow, that’s something I’ve experienced now and then but never really thought about, and other people experience it too, cool!, and Wow, I didn’t know there was a word for that! It’s not surprising that a lot of people didn’t know about this word though, considering it’s only six years old.

It was coined by John Koenig in 2012, as part of his Dictionary of Obscure Sorrows: a project to create English words for feelings that don’t have words to describe them in English. Interestingly though, he’s not just pulling words out of the air, but basing them on words in other languages or earlier forms of English, in order to fairly accurately create words as they might have evolved naturally in English.

Sonder, for example, is related to the German sonder (special), and the Old French sonder (to probe). In fact, it was this latter link which made me think of the word for today’s post. A few days ago I wrote about the word sound, and wondered if this sonder was related to the English sonder. There’s a similar idea of probing behind both, and we can say that we sound someone out in English, meaning to probe them, get an idea of what they’re really like.

And yes, reading about sonder today, I’m happy to see that my guess was, well… a sound one!