Reverse Dictionary: LOVE LETTER

NOUNS
BEHAVIOUR REPORT a love letter → 1947 Amer. sl. (Bk.)
CAPON a ‘billet-doux’; a love letter → 1588 obs.
SUGAR REPORT a love letter → 1947 Amer. sl. (Bk.)
YUM-YUM a love-letter → 1943 naval sl.