When posting about an American snout butterfly recently, I gave its scientific name: Libythaena carinenta. Later I wondered whether that species name might have been based on Latin carīna, meaning ‘keel.’ I still don’t know the answer, but I separately assumed Spanish would have inherited the Latin noun, and in fact it did, in the slightly different form carena. However, Spanish carena doesn’t mean ‘the keel itself of a ship’ but rather, in a definition from the DRAE, ‘parte sumergida del casco de un buque,’ the submerged part of a ship’s hull.’ It can also mean ‘the repair of a ship’s hull to make it watertight.’
That Spanish carena looks a lot like English careen is not just a coincidence. According to the American Heritage Dictionary, the English word comes from the French phrase (en) carène ‘(on) the keel,’ whose main word came from carene, which Old French had borrowed from Old Italian carena, from the original Latin carīna. Careen originated as a nautical term with the sense ‘to incline to one side, or lie over, as a ship when sailing on a wind.’ Another nautical sense is ‘to cause (a vessel) to lean over so that she floats on one side, leaving the other side out of water and accessible for repairs below the water line.’ From the first nautical meaning came the regular English senses ‘to lurch or sway violently from side to side’ and ‘to move swiftly in a controlled or an uncontrolled way.’
If Spanish carena doesn’t mean ‘keel’ per se, how does Spanish say that? The word happens to be quilla, which might make you think Spanish had borrowed the term from English. Actually Spanish took it from French quille. It turns out that both the English and French versions trace back to the Old Norse word for ‘keel,’ kjölr. Those Vikings careened from place to place, no question about it.
© 2018 Steven Schwartzman
Spanish-English Word Connections 
Dec 13, 2018 @ 23:56:26
I found this tidbit that seems to support your hunch: “The specific epithet, carinenta, from the Latin root carin, presumably refers to the keel-shape of the snout.”
I was interested in this: “Careen originated as a nautical term with the sense ‘to incline to one side, or lie over, as a ship when sailing on a wind.’” I’ve never heard the word used that way. The word I learned to use is ‘heel,’ as in ‘angle of heel.’ Each sailboat has a preferred angle of heel, determined by such things as weight aloft and the shape of the hull. One boat I used to sail would lean only about ten degrees; another was happiest at about 20-25 degrees.
When I started poking around, I found this definition of ‘heel’:
“When a ship was made to heel it leaned over, exposing the parts of the hull which usually lay below the waterline.
Vessels were often forced to heel by the pressure of the wind on the sails when they were set obliquely to the hull. They could also be made to heel by moving ballast from one side of the ship to the other, as was done when a ship needed to have the upper part of its bottom cleaned (boot-topped).”
There was a link to an additional source on that page: the Online edition of William Falconer’s Universal Dictionary of the Marine, or, a Copious Explanation of the Technical Terms and Phrases employed in the Construction, …of a Ship.
In that source, I found this: “HEEL, (talon, Fr.) a name usually given to the after-end of a ship’s keel; as also to the lower end of the stern-post, to which it is firmly connected.”
I found ‘careen,’ as well, on page 292.
Now, I can use all three in a sentence: “She careened down the street, heeling to the right and then to the left, until she finally keeled over.”
Dec 14, 2018 @ 09:29:33
I appreciate all your research, including the apparent confirmation that the butterfly’s species name really does refer to its keel-shaped snout. In so doing, you careened from source to source till you were able to come up with that delicious last sentence. Research is so much fun, even if too much might make you keel over.
Dec 27, 2018 @ 00:17:21
It’s amazing how you can see the relationship between these three words and tie all of their meanings together. I know proa (bow, the front of ship), popa (stern, or poop, the back of ship) and quilla (keel). There’s also ‘babor’ (port), and estribor (starboard), and I had to look up the last two.
Dec 27, 2018 @ 00:22:51
Happy tying of the knot! I already knew about careen and learned even more.
Dec 27, 2018 @ 00:35:36
This little article explains the meaning of ‘babor’ and ‘estribor’:
https://goo.gl/BPaXCQ
Dec 27, 2018 @ 10:01:41
Thanks for that good etymological article. I’d have guessed that babor and estribor came from Arabic. What a surprise to find out they’re from English. Spanish speakers may be even more surprised to learn that as common a navigational word as norte also traces back to (Old) English, via French.
Dec 27, 2018 @ 10:13:54
Yes, I remember that post! It was really good, as are all your posts from this blog.
Dec 27, 2018 @ 14:32:57
Thanks for your vote of confidence. I have fun with etymology.