Part of speech: noun
Origin: French, late 17th century
A love letter.
Examples of Billet-doux in a sentence
"I saved every billet-doux I exchanged with my college girlfriend."
"She left only a box of billets-doux from an unknown beau."
Billet-doux developed in French, and translates simply to "sweet note." If you've ever slipped a crush a love letter, then you were handing them a billet-doux.
Did you Know?
Love letters are not just for plot twists in Regency dramas — they also have their place in the White House. Several U.S. Presidents were known for penning billets-doux to their wives and significant others, including John Adams, Woodrow Wilson, and Ronald Reagan.