bread-and-butter letter . bread-and-butter letter {n.} A written acknowledgment of hospitality received. Jane wrote the Browns a bread-and-butter letter when she returned home from her visit to them. Categories: add yours {n.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: B Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Comment on this entry