“Bread and Butter!” That is what people say who are walking along and an obstacle comes between them. They release one another’s hand and walk on either side of the obstacle, then rejoin hands and say, “Bread and Butter”. It’s symbolic. Bread and butter belong together. Another way the term ‘Bread and Butter’ is used is to denote the main substance of an enterprise. “That trick is his ‘Bread and Butter’ trick.” This means that it is the backbone of his act and that he depends on it and relies on it regularly to sustain him.