a plant that has long, sour-tasting red and green stems that can be cooked and eaten as a fruit

Have you ever eaten rhubarb crumble? 你吃过大黄酥皮甜点心吗？

a loud argument

a word that is repeated many times in order to produce the sound of people talking when the meaning of the word is not important

We had to stand at the back of the stage saying "rhubarb, rhubarb" in the crowd scenes. 演到人多嘈杂的场景时，我们都得站在台后模仿“嗡嗡”的嘈杂声。