group

any number of entities (members) considered as a unit

(chemistry) two or more atoms bound together as a single unit and forming part of a molecule

a set that is closed, associative, has an identity element and every element has an inverse

A cluster, crowd, or throng; an assemblage, either of persons or things, collected without any regular form or arrangement; as, a group of men or of trees; a group of isles.

arrange into a group or groups

form a group or group together

To form a group of; to arrange or combine in a group or in groups, often with reference to mutual relation and the best effect; to form an assemblage of.