mass

Think of something large gathered into one whole. A mass can be a big crowd of people, a large amount of something, or a lump or body of material, like a mass of dough or a dark mass in the sky. In science, it also means the amount of matter in an object, such as the mass of a planet.

Sometimes the word refers to a Catholic church service, written as "Mass." If something happens "en masse," it happens all together as one group. So whether you are talking about people, material, science, or religion, the word usually points to size, amount, or many things seen as one.

The word "mass" has several related meanings, and most of them connect to the idea of many things forming one whole. It can mean a large crowd of people, a large amount of something, or a body of material with no clear shape. You might speak of a mass of protesters in the street, a mass of papers on a table, or a black mass of clouds moving across the hills. In these uses, the word suggests size, fullness, or many parts seen together.

In science, "mass" has a more exact meaning. It is the amount of matter in an object. A rock, a truck, and a planet all have mass. In everyday speech, people sometimes mix this up with weight, but they are not exactly the same. Weight changes with gravity, while mass is the amount of matter itself.

"Mass," with a capital M, can also mean the main service in the Catholic Church. This is a separate meaning, but it is very common in religious contexts. There is also the phrase "en masse," which means all together or in one large group.

So the word can point to a crowd, a large amount, a physical property, or a church service. The meanings are different, but they all carry a sense of something substantial, gathered, or important.