# group

Pronunciation: say "GROOP" /ɡɹuːp/

## Noun

1. A number of people or things considered together because they are connected or share something, including a section of a society.
   - Simple: People or things that belong together or share something.
   - _The hikers formed a group near the trailhead._
   - _Several groups of tourists gathered around the monument._
2. A band of performers, usually a small one, who make music together.
   - Simple: A small set of people who play or sing music together.
   - _The group released its first album last spring._
   - _Several local groups competed at the music festival._
4. Several companies under common ownership or control, typically a parent and its subsidiaries, operating as a single business enterprise.
   - Simple: A set of companies that are owned or controlled together and run as one business.
   - _The banking group reported strong profits this year._
   - _Two retail groups merged to expand overseas._
5. A set of teams that play one another within the same division, kept apart from the other sets of teams in that division.
   - Simple: A set of teams that play only against each other in a tournament.
   - _The host nation was placed in a tough group._
   - _Several groups produced surprising upsets in the opening round._
6. A vertical column in the periodic table, containing elements that share similar chemical behavior.
   - Simple: A column in the periodic table that holds elements acting in similar ways.
   - _Chlorine sits in the same group as fluorine and bromine._
   - _The elements of group 18 are the noble gases._
7. A cluster of atoms within a molecule responsible for that molecule's characteristic chemical reactions.
   - Simple: A set of atoms in a molecule that controls how it reacts with other substances.
   - _The carboxyl group gives organic acids their sour, reactive character._
   - _Chemists modify a single group to change how a compound behaves._
8. In mathematics, a set together with an operation that combines any two elements, is associative, has an identity element, and gives every element an inverse.
   - Simple: In math, a set of items with a rule for combining any two, following a few fixed conditions.
   - _The integers under addition form a group with zero as the identity._
   - _Mathematicians classify finite groups by their internal structure._
9. A set of computer users who share the same rights to open, change, and run files and devices.
   - Simple: A set of computer users who all have the same permissions.
   - _The administrator placed the new account in the developers group._
   - _Several groups were created to separate staff accounts from guests._
10. A military aviation formation, typically composed of two or more squadrons.
   - Simple: A unit in an air force made up of several smaller squadrons.
   - _The bomber group lost three aircraft over the Channel._
   - _She was promoted to command an air group of four transport squadrons._
11. Several eighth, sixteenth, or shorter notes joined at the stems; sometimes applied loosely to any ornament built from a few short notes.
   - Simple: Several short notes joined together at their stems in written music.
   - _The pianist rushed through a group of sixteenth notes in the final measure._
   - _Each group is beamed together to show the rhythm._
13. Short for group therapy: sessions in which a therapist leads several people in talking through their problems together. *(colloquial)*
   - Simple: Short for group therapy: meetings where several people talk about their problems together with a therapist.
   - _He's been going to group every week since he quit drinking, and it's helping._
   - _What gets said in group stays in group._

## Verb

3. To put people or things together into a group, or to come together to form one.
   - Simple: To put people or things together, or to come together, in a group.
   - _Editors group related articles under a single heading._
   - _The software grouped the files by date automatically._

## Noun

12. An effective divisor on an algebraic curve: a formal sum of points on the curve with non-negative whole-number multiplicities. *(archaic)*
   - Simple: In math, a collection of points marked on a curve, counted with how often each one appears.

## Other meanings

- (noun) A collection of related rock formations or strata treated as a single stratigraphic unit.
- (noun) A small collection of up to about fifty galaxies that lie near one another in space.
- (noun) The component of an espresso machine from which hot water flows into the portafilter.

## Origin

A Proto-Indo-European root meaning "to crumple, bend" may lie behind it, by way of Proto-Germanic *kruppaz ("lump, round mass, body"), Frankish, and Vulgar Latin. Italian took it as gruppo or groppo, meaning "a knot, heap, group," and French as groupe ("cluster, group"), which English borrowed. The "group theory" sense in mathematics is a calque of French groupe, a term the young mathematician Évariste Galois coined in 1830. Crop and croup are doublets.

Source: DictionaryAI, https://dictionaryai.com/define/group (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).