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How to understand the secret language of the sauna

…and what that tells us about who invented them.

Adam Rang
Adam Rang
Nov 23, 2020 · 8 min read
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Sauna is the most famous Finnish word to enter English. Despite the challenges of 2020, it’s still growing in popularity faster than kalsarikänni (getting drunk at home in your underwear).

Sauna-like sweat bathing traditions actually exist in many different cultures around the world, but the ‘Finnish sauna tradition’ is now the most globally well known.

Early saunas were believed to have been pits dug into the ground and covered with animal skins, much like Native American sweat lodges today. As a result, there’s not a lot of archaeological evidence for them left behind. That’s why the language of the sauna is important. Language is data and we can learn so much through it.

So let’s look at where the word ‘sauna’ comes from and also, just as interestingly, where the word for ‘sauna steam’ comes from. Bizarrely, they come from very different places — and perhaps for good reason.

The birth of ‘sauna’

Although no one has done more than the Finns to preserve and share sauna culture globally, it’s actually more accurate to talk about the ‘Finnic sauna tradition’ than the ‘Finnish sauna tradition’.

Sauna comes from the Proto-Finnic word, Sakna. This word would have been used by the Proto-Finnic people as they migrated west from the Urals and settled into North-Eastern Europe around the Baltic sea. When exactly that happened is still hotly disputed by historians (even when they’re not in the sauna), but it was at least many thousands of years ago and long before the creation of our nation states and the peoples they would be named after.

It was only after arriving in the Baltic sea region that those early Finnic people then split up again into multiple Baltic-Finnic peoples, which all developed similar but distinctive languages and cultures. Spoiler alert: Two of them now have their own states, Finland and Estonia, but many others are at least officially recognised minorities with varying levels of autonomy. Similar words for sauna exist in all these languages, such as saun in Estonian.

Already, this is helping us date the sauna tradition — or at least the language of the sauna.

So where did early Finnic peoples get the word sakna from? Strangely, it didn’t come with them from the Urals. It’s not Finno-Ugric, which is the wider language and cultural group they descended from. Instead, it’s borrowed from very old Germanic. Consider the English word stack. That comes from the Old Norse word stakkr, which comes from Proto-Germanic stakka, which comes from Palaeo-Germanic stagna. Somewhere along the way between Palaeo and Proto Germanic, this word entered early Finnic as sakna, which became sauna.

In English, stack and sauna are doublets. Those are words with different meanings that enter a language from the same source. That’s particularly interesting as stack can be used in contexts that relate to saunas, such as ‘a stack of stones’ or ‘a chimney stack’. There’s one more doublet to these words in English though, which is potentially mind-blowing…


The Romans developed stoves inside for heating, not cooking, so the word stove and other variants across German and Romance languages actually does refer to a hot air or steam bath. So stove is basically an early English word for a sauna. We swapped it later for sauna because we simply forgot how to sauna, until the Finns reminded us.

Now let’s look at things from another angle. A sauna to most people around the world today is just a hot room. To Finnic peoples, it’s quite a bit more because we have specific words for different rooms inside the sauna, as well as different words for aspects of the tradition that don’t exist in other languages.

The most important of these is the steam. So let’s break down the etymology of that too. I actually think that’s much more interesting.

Understanding leil

We created this picture below to map out words for ‘sauna steam’ across surviving Finnic languages. The Sámi are a bit of an anomaly because they split off earlier, but still have a related word.

The map is a work in progress, but hopefully some of you reading this will have some corrections or feedback. Then I can hire someone with better graphic design skills to make a nicer looking version!

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Even here in Estonia, there are so many dialects and probably many more words for ‘sauna steam’ that we’ve probably missed. In addition to leil in Estonian, which is our standardised state language also known as ‘North Estonian’, we were able to count three words used in the Võro region (which is a nation within our nation) and one in the Seto Kingdom (which is a nation with that nation within our nation). Huge thanks to Eda from Mooska smoke sauna and Seto Tour Guide Helen for their help with these.

The first person I showed this to said: Ah, it’s like all those Iniut words for snow. Not quite. These words aren’t types of sauna steam. They all have the same meaning, but show the different languages that evolved with this same sauna culture. In fact, I can think of one additional word for a different type for sauna steam in Estonian. We use karm to refer to the first steam in a smoke sauna, which we need to expell because it contains ash and soot. Only after that does the pure sauna steam become leil.

All these words originate from the Proto-Finnic word, leülü.

As you’re an English speaker reading this, you probably think these words are very difficult to pronounce. That’s because, unlike sauna, this word wasn’t borrowed from Germanic or any other Indo-European language source. Instead, it came with these early Finnic peoples from the Urals to the east.

Finnic peoples around the Baltic descend from the Finno-Ugric peoples who in turn descend from an Uralic people who lived somewhere around the Ural mountain range and spoke Proto-Uralic.

Leülü in Proto-Finnic comes from lewle in Proto-Uralic. However, the Proto-Finnic word seems to be the first reference to ‘sauna steam’, while the Proto-Uralic word means ‘spirit’ or ‘soul’. This is not in a heavenly supernatural sense, but in the sense of what it means to be alive. That’s why this same word in Proto-Uralic also forms the word ‘to breathe’. All other Finno-Ugric peoples from Hungary to deep into Russia on the other side of the Urals still use words that look like variants of our Finnic words for ‘sauna steam’ but actually refer to that original meaning. However, if anyone can help fill the gaps, I’d love to learn more about ancient bathing traditions among other Finno-Ugric peoples and the language used to describe it.

For reference, here you can see all the Finno-Ugric peoples with the Finnic peoples in blue, along with the Sámi in pink.

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Every language is a unique way of seeing the world. Language is also data, which if read correctly, allows us see back into the past.

Google ‘who invented saunas’ and all the top answers will say it happened by Finns or in Finland. But, as we’ve seen, this is a vast oversimplification of history.

Early Finnic peoples were talking about their saunas a very long time before the notion of the Finnish people existed and possibly before they even reached Finland. We know that these early Finnic peoples assimilated with existing peoples living in the Baltic sea region when they arrived. Based on the linguistic evidence, it’s possible that they adapted the sauna tradition from those people and infused it with their own cultural worldview, hence the different etymology for ‘sauna’ and ‘sauna steam’. This is just a guess. There are more clues to the origins of the sauna, which I can go through in future articles.

I actually think the naked truth about saunas is even more amazing, including to Finns. ‘Who invented the sauna’ is perhaps a question that we will never be able to truly answer — and perhaps it’s not too important anyway. It goes so far back in time then no one can claim credit for that. What’s more important is keeping the tradition alive. The sauna is part of our common human heritage and it is mostly due to the Finns — and the survival instincts of other Finnic peoples — that we can still enjoy it today and share it with the world again.

Feedback to this article

There’s been a great response online since first posting this article. One interesting observation is that the Estonian ‘leil’ is a bit of an outlier, as with many other words, because it reflects the slight Germanisation of the language, which is why English speakers will find it easiest to say.

Also, thanks for all the ideas to make more maps for other words, such as the bundles of branches we use to beat ourselves in the sauna (viht, vasta, vihta, vennik, etc). We’ll do that too in addition to making this map nicer.

A few points to common responses: Linguists still argue about how different language groups evolved and use different terminology. The term ‘Finnic’ in this article is also often called ‘Baltic-Finnic’. It’s the same category, a later subdivision of ‘Finno-Ugric’. Some have pointed out that there are more words in other Finno-Ugric languages, like lélek in Hungarian. Actually, these words are used in their original Proto-Uralic context of spirit / to breathe, which is why they provide a crucial clue that sauna culture as we know it today probably developed alongside Finnic migration into the Baltic region.

One person commented to say that ‘sauna steam’ is actually not a good translation. He gave an example from Christian terminology. Talking about leil/löyly as sauna steam is like referring to the Holy Communion as bread and water. It’s a bit too literal, basically, while not reflecting the huge cultural and spiritual significance of the word. It’s a fair point.

I’ve also corrected ‘Eskimo’ to ‘Inuit’. Here’s why.

One final point: If you are an English speaker who likes a good sauna then you may feel like you need a word for sauna steam too. Don’t worry. You can use ours!

Thanks for reading

This Estonian Saunas blog is run by Anni and Adam. We export Estonian sauna design, technology, & culture at

You can follow our adventures on Instagram, Facebook, YouTube and Twitter. We also have a Facebook group for Sauna Builders & Explorers.

You can also contact us at

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Estonian Saunas magazine

We export Estonian sauna design, technology, & traditions.

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