Meaning of bread and butter

bread' and but'ter

Pronunciation: [key]
  1. bread spread with butter.
  2. a basic means of support; source of livelihood; sustenance: The automobile industry is the bread and butter of many Detroiters.

bread-and-but•ter

Pronunciation: (bred'n but'ur), [key]
— adj.
  1. providing a livelihood or basic source of income; supplying the basic needs of life: a bread-and-butter job; the agency's bread-and-butter account.
  2. of or pertaining to basic needs: housing and other bread-and-butter political issues.
  3. basic or everyday; staple; routine.
  4. expressing thanks for hospitality: a bread-and-butter letter.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.