Today's word is not one to use in polite company: ett knull means 'an act of sexual intercourse'. The one-word English translation would be 'fuck', except it's probably even more vulgar (knull is never used in any other context, like 'fuck' can be used as an expression of frustration, surprise, or an intensifier).
It's been used in Swedish for centuries, and comes from the verb knulla.
As we all know, Swedish speakers love compound words, and yes, knull appears in plenty: knullkompis (fuck buddy), knullbar (fuckable), knullrufs (bed hair).
Knull is coming
Me who speaks Swedish ??? pic.twitter.com/VWMDlZ9anb— Axl (@N7Ace) July 2, 2020
Well, when Marvel Comics launched an ad campaign to tease a new villain arriving to their universe this year, the slogan was “knull is coming” (that's the name of the character). Needless to say, they probably didn't get the reaction they intended from their Swedish fanbase.
But we know what you're really interested in – the linguistic history of knull, of course!
You can also use knull to talk about a person you've had sex with, although it's quite derogatory for obvious reasons.
But it didn't always have a sexual connotation, since it originally meant 'to bump' or 'to push'. It comes from an Old Germanic word, and is related to the verb knüllen in today's German, which might make Swedish speakers giggle but actually means “to crumple”.
One of the earliest recorded uses of Swedish knull was in, believe it or not, a bible from the 1500s. But it was used as an onomatopoetic verb describing the sound a pigeon makes.
Slowly it entered the Swedish vocabulary as a euphemistic term for sex, and during the 1600s it wasn't seen as vulgar, but can be found in old love poetry. These days, we'd suggest you avoid that unless you really, really know your audience.
I had an old friend with whom I used teach skiing here in Scotland in the mid-1970s, and with whom I used to get up to no end of drunken mischief those days. In late 1979 we both pitched up independently in Sweden, though in different cities (I in Stockholm, he in Gävle). He had worked there some years previously and spoke pretty good Swedish, while I was learning the language in evening classes and using an audio tape course (yes, that’s how we did it those days). In midsummer 1980 we went skiing up in Riksgränsen, a story I recently recounted with pictures on my Facebook page on the 40th anniversary of the trip, which is why it’s fresh in my memory after all those years. We had a mutual pal back in Edinburgh who published a monthly Scottish skiing newspaper called “Inside Edge”. My pal used to write a column on skiing in Sweden for the paper, under the pen name of “Max Knull”. He told the owner what it meant in Swedish, and of course I knew as well, but none of the rest of the readership did.
Just one of the advantages of multilingualism… understanding other people’s jokes!