bread and butter
Definition from Wiktionary, the free dictionary
See also: bread-and-butter
- Used other than as an idiom: see bread, butter.
- (idiomatic) 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.
See also bread-and-butter