The British Idiom – Bread-and-butter
Definition of Bread-and-butter
Your bread-and-butter is the source of your income.
Examples of Usage of Bread-and-butter
These websites are my bread-and-butter. Mobile phones used to be the company’s bread-and-butter, but now they diversified into tablet PCs as well.
Now watch my YouTube video English lesson which contains this British English idiom.