What does the word R mean?

Usage examples for R

  1. " Marr was at Lisner's house. – The Desire of the Moth; and The Come On by Eugene Manlove Rhodes
  2. 1880 May On the Preparations to be made for R. Astr. – Autobiography of Sir George Biddell Airy by George Biddell Airy
  3. In 1857- 1865 appeared the first good American edition of R. G. White. – An Introduction to Shakespeare by H. N. MacCracken F. E. Pierce W. H. Durham