group

Concise Oxford English Dictionary © 2008 Oxford University Press:
group/ɡruːp/

▶noun [treated as sing. or pl.]

• 1 a number of people or things located, gathered, or classed together.

• 2 a number of musicians who play popular music together.

• 3 Chemistry a set of elements occupying a column in the periodic table and having broadly similar properties.

• 4 Chemistry a combination of atoms having a recognizable identity in a number of compounds.

• 5 Mathematics a set of elements, together with an associative binary operation, which contains an inverse for each element and an identity element.

• 6 a division of an air force, usually consisting of two or more stations.

▶verb place in or form a group or groups.

– derivatives
groupage noun,
grouping noun.

– origin C17: from Fr. groupe, from Ital. gruppo, of Gmc origin; rel. to crop.