If something is hollow, it means that it’s empty or that it has a cavity inside. If a surface is hollow, it has a curve inward or downward or it is somehow sunken. Sounds can also be hollow, meaning that they are not resonant. Figuratively, hollow means…
A rock is, of course, a large mass of stone that forms a hill or a cliff or a piece of stone. Colloquially, a gemstone, especially a diamond, is also called a rock. As a verb, unrelatedly, to rock means ‘to move gently from side to side’ and also ‘to shake violently.’ It is also a synonym for shake, in the sense of being moved by great emotion. As a noun, rock is not only a rocking movement but also…