https://unix.stackexchange.com/questions/3467/what-does-rc-in-bashrc-stand-for
It looks to me that while the origin definitely seems to be "runcom", files that end with "rc" are used today in a more general way, i.e. as a "run configuration", as several have already pointed out. One example I recently came across is ".vuerc", a file used by the vue.js framework's CLI to store user defined configuration presets for creating new projects and other settings for the runtime. ".vuerc" is a JSON file, i.e. NOT a script of runnable commands.
