An assemblage of persons or objects gathered or located together; an aggregation: a group of dinner guests; a group of buildings near the road. Two or more figures that make up a unit or design, as in sculpture. A number of individuals or things considered together because of similarities: a small group of supporters across the country. Linguistics A category of related languages that is less inclusive than a family. A military unit consisting of two or more battalions and a headquarters. A unit of two or more squadrons in the U.S. Air Force, smaller than a wing. A class or collection of related objects or entities, as: Two or more atoms behaving or regarded as behaving as a single chemical unit. A column in the periodic table of the elements. A stratigraphic unit, especially a unit consisting of two or more formations deposited during a single geologic era. Mathematics A set with a binary associative operation such that the operation admits an identity element and each element of the set has an inverse element for the operation. Of, relating to, constituting, or being a member of a group: a group discussion; a group effort. To place or arrange in a group: grouped the children according to height. To belong to or form a group: The soldiers began to group on the hillside.