Here’s an example:

M-x, “apropos”, RET, “copy text”

No apropos matches for “copy text”

Using just “copy” returns two undocumented variables first. I did eventually find kill-ring-save, but it took more digging than I’d like. Obviously if I embraced (or at least remembered) Emacs’s terminology I’d have a better experience, but I’m not there yet.

Edit again: “copy selection” found copy-region-as-kill, which is maybe what I should have searched for originally. Not sure yet how it differs from kill-ring-save.