Is there a term in linguistics for the evolution of a word like “space ship” to “spaceship”? There’s an answer on this site which says:
Here is a rule I read related to evolution of compound words.
Most compound words start out as two words: Air plane, Space ship
Stage two, they are hyphenated: Air-plane, Space-ship
Stage three, over time they start become accepted as a single word: Airplane, Spaceship
I was wondering if there’s a term for this evolution process, to know what term to search for to learn a bit more about it. I vaguely remember reading something like the above before, and had assumed it works that way “as a rule”. But it’s interesting to see the rule doesn’t really seem to apply for the “spaceship” example to begin with: the Google Ngram looks more as if usage of both “space ship” and “spaceship” initially increased in tandem, rather than one preceding the other. A Google Ngram for “spacecraft”, on the other hand, seems to show it didn’t really go through a stage of being “space craft”. It would be interesting to learn more about why different words (especially words as similar as “spaceship” and “spacecraft”) evolve differently in this sense.