break someone up
1. verb To come apart in pieces. The house is so old that the plaster on this wall is breaking up—there are bits of it all over the floor.
2. verb To split something into smaller pieces. In this usage, a noun is commonly used between "break" and "up." I know the project is daunting, but let's break it up into manageable parts that each of us can work on. Because there was only one cookie left, I broke it up so that each kid could have a piece.
3. verb To be inaudible or indecipherable, as of a voice on the telephone or a broadcast of some kind. I'm sorry, can you repeat that? You're breaking up. Your father called, but he was breaking up the whole time, and his message was all garbled.
4. verb To disrupt something and induce its end. In this usage, a noun can be used between "break" and "up." When the teacher saw the two boys shove each other, she came running over to break it up. The police have been working hard to break up the drug trade in our city
5. verb To end a partnership of some kind, often a romantic relationship. I'm so sad to hear that Mara and John broke up—I thought those two would be together forever. The Beatles breaking up is considered a pivotal moment in rock history.
6. verb To cause one to laugh or cry intensely. In this usage, a noun or pronoun is commonly used between "break" and "up." That joke broke her up more than I'd anticipated—she thought it was hilarious! My mother was fine this morning, but the funeral really broke her up.
7. verb To laugh or cry intensely. She thought that joke was hilarious and completely broke up at it! My mother was fine this morning, but she really broke up at the funeral.
8. verb To disrupt the monotony of something. I need to walk around and get some coffee—anything to break up a morning of research. You need to inject some humor and break up the dull tone of this speech.
9. noun The end of a partnership of some kind, often a romantic relationship. In this usage, the phrase is commonly written as one word. I was so sad to hear of Mara and John's breakup—I thought those two would be together forever. The Beatles' breakup is considered a pivotal moment in rock history.
break someone up
see under break up, def. 5.