A curious etymological fact popped up on HH last week: a lake was originally a stream.
Pithy little stop-you-in-your-tracks-how-can-that-be-right facts like these always go well on HH—so well, in fact that (Shameless Plug #452) you can read the stories behind 100 of them in The Accidental Dictionary.
But this lake vs. stream one didn’t make the final cut there, so here’s a bit more about it now. And brace yourselves—this one’s a bit complicated...
So. There was a word back in Old English, lacu, that, despite its similarity to our word lake, was basically a general term used to refer to all kinds of different watercourses and water features. But all the earliest records of the word lacu refer to streams, so we can deduce that this was probably the word’s original meaning: in that context, lacu has been tracked down to a document dating way back to the mid tenth century that talks of a group of people fording a stream somewhere along the banks of the Thames.
Like most Old English word, the earlier origins of lacu lie on the continent. It’s a Germanic word, and is probably distantly related—via some impossibly ancient word root denoting “water” or “moisture”—to more familiar words like leak, leech and leach.
At this point, we need to leave lacu to one side and fast forward to the Middle English period. It was around then that the English language picked up a word from French, lac, that meant “pool” or “pond”. Despite its similarity to the Old English lacu, French lac had its origins in Latin, and so was set apart from the Germanic origins of Old English.
So that means that by the late eleventh century, there essentially existed two distinct words in English—lac and lacu—that had entirely different origins, somewhat similar meanings, and even more similar spellings. As a result, things started to get a bit muddled.
Before long, Old English lacu and French lac began to morph into and cross over one another, and their meanings and spellings began to become ever more alike. Eventually, they both began to be spelled lake—and the word finally established itself in the language as just another word for a large, enclosed body of water.
So that word lake we still use today? It essentially has two ancestors: one, an Old English word used that originally meant “stream”, the other a later French word of Latin origin that has always referred to enclosed pools or ponds.
That’s not to say that Old English lacu vanished completely from the language, however. As some of you pointed out on Twitter, the use of lake to mean “stream” can still be found in place names like Newlycombe Lake in Dartmoor—which continues to surprise walkers and ramblers by being a small stream, not a lake.
So you might not come across it very often, but that original lake still lives on in English today.