English is a strange language. We have words that have multiple meanings, and which meaning is relevant often depends on context. However, sometimes the context gets mangled in editing, such as when an editor is trying to shorten headline. The results are sometimes quite humorous.
The proper historical term for this is "syntactic ambiguity," but "crash blossom" is much easier to remember. The term was coined in 2009, when Mike O’Connell saw a headline that read, "Violinist Linked to JAL Crash Blossoms.” The article was about the flourishing musical career of Diana Yukawa, who lost her father in the infamous 1985 Japan Airlines plane crash. But on seeing the headline, O’Connell's first thought was, "What's a crash blossom?" The headline uses no articles or conjunctions, so it's easy to see "linked" as the verb instead of "blossoms."
The origin story is perfect, because the resulting term is delightfully descriptive. The words crash together until some new and different idea blossoms from it. Language Log notes that these headlines were previous called "garden paths" because they led you down a path to a place different from where you should be.
Hey, little Star Trek fan, the good news is that Patrick Stewart has a surprise for you! The bad news is that he's brought you a life-threatening disease! Minnesotastan at TYWKIWDBI posted this image and referred to a long list of crash blossoms.
Poor laser lost his job. He was just too powerful.
The line breaks in this headline lead one to think the tumor fought back. Let's see if we can improve this headline by adding some English grammar. Oh! The first line of the story makes it perfectly clear that the boy was the one fighting back, not the tumor. And the boy now has a black belt, not the tumor. The headline writer just dropped a few words to make it fit. Those were important words, though. This one was found at Bad Newspaper. And so was this one.
You can imagine the kind of person who would respond to that kind of recruitment. You can find a lot more crash blossoms at Language Log.