Although you might think they are related by just looking at their spelling and their meanings, the words «island» and «isle» are surprisingly not related at all.
Their looks and meaning are however not the only thing they have in common – their origins are equally interesting. Let’s take a look.
The word «isle», meaning an island, usually a small one, comes from the Latin word «insula», an island.
The word entered the language in the late 13th Century from the Old French word «isle», island.
Notice how the word does have an s. That was just a written remnant of an older [s] sound in the French language that by the time had already been dropped.
When it was borrowed into the English language, the English word would not be pronounced with the sound either but it would keep the same spelling.
The word in today’s French is written with a circumflex, «île», indicating that there used to be an [s] sound that was dropped at one point, referencing the old form «isle».
That explains the mystery of why the s in «isle» is silent.
Since the word can be traced back to Latin, it’s obvious why cognates are abundant in other Romance languages. The Spanish «isla», the Italian «isola», the Catalan «illa» and the Portuguese «ilha» are some of them. All of these bear the meaning of island.
English is however not the only Germanic language with a word meaning island derived from the Latin «insula». German, for example, uses the word «Insel», which comes from the Old High German «ī̌sila», which at the same time derived from the Latin word.
The German word came straight from Latin and that explains why the word does have the sibilant sound.
Now, what’s the deal with «island»? Well, let’s start exposing the true identity of the word.
«Island» wasn’t always written like this – it was actually spelled «yland» not too long ago. And this one came from the Old English «igland» or «iegland», an island.
«Yland» and «iegland» already look quite different from the Latin counterpart «insula». The reason is, they are not related at all.
Looking at «iegland» we can easily tell the word might be a compound, from which one component seems to be «land».
This is actually true. The word is composed by «ieg», an island, and «land», ground, soil or portion of earth.
«Ieg» in Old English comes from the Proto-Germanic «*awjo», a thing on water.
While it might seem weird that Old English had two words for island, «ieg» and «iegland», literally “island-land“, the explanation is quite easy. The word «land» was attached to «ieg» to differentiate it from other homonyms, or words that are pronounced the same, especially from the Old Engslih word «ea», meaning running water.
The Old English «ea» actually came from the Proto-Germanic «*ahwo» and it, as well as «*awjo», are believed to have derived from the Proto-Indoeuropean root «*ekweh-». This one is the same root that would give us the Latin word «aqua», for example, too.
The reason why the English «island» is written with an s is because of a modification in the 16th Century due to the similarity to «isle».
But if that is the case cognates in other Germanic languages must exist without the s in them, right?
The truth is, the do exist – plenty of them. The German «Eiland», the Old Frisian «eyland», the Danish «öland» and my favorite ones, the Norwegian «øy» and the Icelandic «eyja».
But we are not finished yet. I have been avoiding it until now but I’m pretty sure you have asked yourself the question many times:
What about their Proto-Indoeuropean origins? They must be related if we go further back in time.
Well, no. You see, while the Germanic variants of the word can be clearly traced back to a common Proto-Indoeuropean ancestor, the Latin «insula» cannot be really traced so far back.
Let me explain. We have seen how the English «island» comes from «eigland», with is a compound of «eig», derived from the Proto-Germanic «*awjo», and «land».
«Land» comes from the Proto-Germanic «*landja-», which is believed to have derived from the Proto-Indoeuropean root «*lendh-», with the meaning of an open land. This is however just a theory.
«*Awjo» comes from the Proto-Indoeuropean root «*ekweh-», meaning water.
Even though «*ekweh-» gave us the Latin word «aqua», water, it is a bit difficult to picture how the word evolved into «insula», especially if we take into consideration the fact that both words existed at the same time in the Latin language.
The actual origins of the Latin «insula» are sadly unknown, which makes the matter more confusing. However there is a somewhat believable theory that the word could have evolved from the Latin expression «in salo», in the salty water or in the sea.
Another theory is that the word may have evolved from a loanword, borrowed from an unknown foreign word. It is also theorized, the same word would have given us the Old Irish «inis», the Welsh «ynys» and the Greek «nēsos», all of which mean island.
So after digging so deep, we can see how there is nothing indicating at a possible common origin for the English words «island» and «isle». The fact that they look so similar and mean almost the same is just a coincidence that happened over time.
But who knows, perhaps «insula» came from a word that somehow also derived from the Proto-Indoeuropean «*ekweh-» or «*lendh-», making the two English words cognates. Although highly unlikely, I guess we will probably never know.