To interrupt someone who is speaking. She was about to explain her point when he rudely cut in.
To move into a line of people or vehicles, often without permission. The car cut in front of us, causing us to brake suddenly.
To include someone in a share of profits or benefits. He decided to cut his partner in on the deal.
To blend or mix ingredients, especially in cooking. You need to cut in the butter with the flour until the mixture resembles breadcrumbs.