Epidemiologists refer to a group of cases of the same disease or condition in a particular area as a cluster.

The protons and neutrons cluster together in the center of the atom in what is called the nucleus. The electrons orbit around the nucleus.

Sami saw a cluster of kids standing on the balcony.

It was a complete clusterfuck.

I look out on the brilliant heaven, and see a milky way of powdery splendour wandering through it, and clusters and knots of stars and planets shining serenely in the blue frosty spaces; and the armed apparition of Orion, his spear pointing away into immeasurable space, gleaming overhead; and the familiar constellation of the Plough dipping down into the west; and I think when I go in again that there is one Christmas the less between me and my grave.

The massive spider seen crawling across the sky on a glowing web is pure fiction, but the concept alludes to something called the cosmic web, which is the large-scale organization of matter and dark matter in the universe: Thin filaments of normal matter and dark matter connect clusters of galaxies, like roadways between major cities.

A galaxy is a cluster of stars, dust, and gas which is held together by gravity.

The stink bug can hide in wine grape clusters and then taint the juice when the grapes are crushed.

A cluster of sores decorated the skin.

The farmland was open and flat, except for the solitary house in a cluster of trees.