Definition of "bread and butter" in English

Noun

1. That which is central or fundamental, as to one's business, survival, or income; a staple or cornerstone.

   • They will do some machining if you ask them, but sheet metal has always been their bread and butter.

2. The basic requirements of living, such as food and housing.

3. Used other than figuratively or idiomatically: see bread,‎ butter.

Interjection

1. Said when two people walking together are temporarily separated by an obstacle in order to indicate that they belong together.