"Careen" vs. "career"

Yesterday while I was doing the across clues in a crossword puzzle, the error checker alerted me to a mistake.  I had entered "careen" but it wanted "career."  Not understanding the difference, I took a screencap and moved on.  This morning I was still puzzled, so I turned to Merriam Webster for info:

"The similar-sounding verbs careen and career are often used interchangeably, meaning "to move at top speed," often in a reckless or out-of-control manner.

Despite their one-letter-off resemblance, careen and career are not etymologically related. Career finds its origins in medieval jousting tournaments. Before it came to be the preferred term for one's professional path, the noun career (from Middle French carriere) referred not only to the courses ridden by knights but also the act of riding a horse at a rapid clip in short bursts.

The verb careen, meanwhile, originally described the action of putting a ship or boat on land, usually in order to clean, caulk, or repair the hull. So how did this verb get conflated with career?  To careen a boat, you need to tilt it on its side. Careen gradually became used to describe the act of a boat tipping over in rough waters, or the similar tilting of other things... As motor vehicles became commonplace, careen became a useful word to describe the lurching, side-to-side motion that a vehicle would make when it was racing out of control, thus the overlap between careen and career.

Traditional usage commentators frown upon this overlap, insisting that careen shouldn't be used for something that is only moving at a headlong pace without any kind of side-to-side motion. But popular use tends to drown out those objections. Nowadays, careen is actually the preferred verb for rushing forward, particularly in American English.

Illustrative examples at the source.  Very interesting.  You learn something every day.