"Unflavored" 和 "plain" 中文怎麼說?
In your case, we won’t say it’s unflavored. We will just say it does not have fillings: 那些小小的圆子没有馅儿,大的汤圆里有黑芝麻馅儿
Usually, we call the one with filling 汤圆 and the small one 小圆子 (I am from Shanghai. I am sure different places can have slightly different names, like some others debated below, the difference between 元宵 and 汤圆.)