For what does "Rcon" stand for in Rijndael/AES? How do we expand the abbreviation “Rcon” used in the Rijndael key schedule?

I know what it is, I know how it works; I just do not know for what it is a shortcut for. I mean: if "Sbox" is "Substitution box", then "Rcon" stands for… ?
Quoting from FIPS 197 (PDF), on page 11:


  Rcon[]   The round constant word array.


So, the answer is obviously "round constant".