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.

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

   This movie is a love letter to New York.

• billet-doux

• French: lettre d’amour
• German: Liebesbrief
• Italian: lettera d'amore
• Portuguese: carta amorosa
• Russian: любо́вное письмо́
• Spanish: carta amorosa, carta de amor