> Another shrug, but part of it is that the PL community (programming language community) is pretty deep into its own jargon that doesn’t have as much overlap as you might think, with other subfields of computer science.
The word reified dates back to the 1800s. It isn't the most common word, but it also definitely wasn't invented by the programming language community.
It was (and is) used a lot by philosophers and there was a large overlap between a certain class of philosophers and a certain class of mathematicians who developed early type theory. Any type theorist who knows his literature will run into reification very early on.