love letter

love letter (plural love letters)

1. A letter written about the author's love for the intended reader.

   We never see each other, but have been sending love letters every Valentine's Day for 10 years.

   • 1892, Walter Besant, “Prologue: Who is Edmund Gray?”, in The Ivory Gate: A Novel, New York, N.Y.: Harper & Brothers, […], OCLC 16832619:

     Thus, when he drew up instructions in lawyer language […] ; his clerks, however, understood him very well. If he had written a love letter, or a farce, or a ballade, or a story, no one, either clerks, or friends, or compositors, would have understood anything but a word here and a word there. For his signature, however, that was different.

   • 2013 June 14, Jonathan Freedland, “Obama's once hip brand is now tainted”, in The Guardian Weekly, volume 189, number 1, page 18:

     Now we are liberal with our innermost secrets, spraying them into the public ether with a generosity our forebears could not have imagined. Where we once sent love letters in a sealed envelope, or stuck photographs of our children in a family album, now such private material is despatched to servers and clouds operated by people we don't know and will never meet.

2. (figuratively) A work that shows great passion or enthusiasm for something.

   This movie is a love letter to New York.

• billet-doux