dog's letter (dogz LET-uhr) noun
The letter R.
[From Latin littera canina, literally dog's letter. In Latin the sound of the letter R was trilled. Think Grrr! of a snarling dog. A good example of a trilling R is none other that the Spanish word for a dog: perro.]
-Anu Garg (words at wordsmith.org)
"There is only the difference of the dog's letter between friend and [fiend]." The Westminster Review (London, UK); 1830.
Faith which does not doubt is dead faith. -Miguel de Unamuno, philosopher and writer (1864-1936)