DutchLatin or Breton1 syllable
Meaning: just and fair, or from an old Breton word for lord.
Joost
Joost has two possible origins and no way to choose between them. It is either the Latin Justus or the Breton saint Judocus, and by the time Dutch got hold of it the two had already merged.
| Origin | Dutch — from Latin Justus, or from Judocus, a Breton saint's name; both fed the same Dutch form |
|---|---|
| Meaning | If Justus, then just, fair, righteous. If Judocus, then from the Breton element iud, lord |
| Pronunciation | YOHST — one syllable. Dutch oo is a long pure o, the vowel of English boat without the glide; the oo of boot is spelled oe in Dutch |
| Popularity | Outside the current U.S. top 100; a solidly Dutch name that has never travelled |
| Variants | Joos, Justus, Judocus, Jost, Josse, Joyce (which was a man's name in medieval England) |
| Nicknames | Joost is already short; Joosje is the affectionate form |
| Idiom | Joost mag het weten is Dutch for heaven knows |
History & meaning
The Latin road is simple: Justus is an adjective meaning just or righteous, a favourite among early Christians and the name of several saints. The Breton road is stranger. Judocus was a seventh-century prince of Brittany who turned down a crown, walked to the Channel coast and lived as a hermit; the place where he settled is still called Saint-Josse-sur-Mer. His cult crossed to England and the Low Countries with Breton and Norman monks, and his name produced French Josse, medieval English Joyce and Dutch Joos. Latinised as Iudocus, it sat close enough to Iustus that scribes stopped distinguishing them, and by the fifteenth century no individual Joost can be assigned to one source or the other. Anyone who says the name definitely means just is picking a side the evidence does not support.
Then there is the phrase. Joost mag het weten, literally Joost may know it, is what a Dutch speaker says where an English one says heaven knows or search me. The usual explanation sends it east: Dutch sailors in the Indies picked up a Javanese word for god derived from Portuguese Deus, and the Joost of the phrase was originally the devil. Dictionaries mark the account uncertain, and a simpler reading exists, that an ordinary name was substituted for a dangerous one, the instinct that gave English the deuce.
Why parents choose it
Joost closes on a cluster, which gives it more force than most one-syllable Dutch names, and the vowel is easy for foreigners once they stop reading it as boost. In a country of names with tidy meanings, there is something appealing about one that has kept its options open for six hundred years.
Middle names for Joost
That -st ending is a wall, so a middle name opening on a vowel does the most work: Joost Abel, Joost Elias, Joost Amos, Joost Reinier. See the middle names guide.
Famous Joosts
Joost van den Vondel is the towering figure of Dutch literature, a poet and playwright whose Gijsbrecht van Aemstel opened the Amsterdam theatre in 1638 and was staged every New Year for three centuries; the Vondelpark is named after him. Joost Luiten has won several times on the European Tour. Joost Klein, a musician from Fryslân, represented the Netherlands at the Eurovision Song Contest in 2024 with Europapa.
Consider instead
Joris is its neighbour in the Dutch J names and comes with a dragon. Jasper is the same era of Dutch name and already at home in English. Rens is shorter and blunter.