For the meaning of rc you have probably seen:

  • run commands
  • resource control
  • run control
  • runtime configuration

I’d like to go with runcom since as seen in this source: Unix faqs:

rc (as in “.cshrc” or “/etc/rc”) = “RunCom”

“rc” derives from “runcom”, from the MIT CTSS system, ca. 1965.

‘There was a facility that would execute a bunch of commands stored in a file; it was called “runcom” for “run commands”, and the file began to be called “a runcom.”

“rc” in Unix is a fossil from that usage.’

— Brian Kernighan & Dennis Ritchie, as told to Vicki Brown

Also ESR states that in Run-Control Files:

[101] The ‘rc’ suffix goes back to Unix’s grandparent, CTSS. It had a command-script feature called “runcom”. Early Unixes used ‘rc’ for the name of the operating system’s boot script, as a tribute to CTSS runcom.

So my mind is set to runcom.

All done!