rēs : "thing"

r noun

     1a: the 18th letter of the English alphabet
      b: a graphic representation of this letter
      c: a speech counterpart of orthographic r

     2 : a graphic device for reproducing the letter r

     3 : one designated r especially as the 18th in order or class

     4 : something shaped like the letter R

“R.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/r. Accessed 3 Jul. 2023.