group Definition

1. A number of people or things gathered, placed or classed together.

Thesaurus: gathering, assemblage, congregation, crowd, gang, team, squadron, clique, circle, faction, coterie; category, class, division, set, branch.
2. A number of business companies under single ownership and central control.

Form: Group (sometimes)
3. A band of musicians and singers, especially one that plays pop music.
4a. A division of an air force consisting of two or more wings;
4b. A division of the US air force subordinate to a wing;
4c. A division of the US army consisting of two or more battalions.
5. chem.
In the periodic table: a vertical column representing a series of chemical elements with similar chemical properties.
6. chem.
A combination of two or more atoms that are bonded together and tend to act as a single unit in chemical reactions.

tr & intr
grouped, grouping
1. To form (things or people) into a group.

Thesaurus: mass, assemble, collect, band, marshal, get together, fraternize, congregate; classify, categorize, sort, order, cluster, arrange, assort.

See Usage Note at collective nouns.