1. Any number of entities (members) considered as a unit
   "The flock of birds moved as a single group";
   - grouping
    
2. (chemistry) two or more atoms bound together as a single unit and forming part of a molecule
   "The hydroxyl group is an important chemical group in many organic compounds";
   - radical, chemical group
    
3. A set that is closed, associative, has an identity element and every element has an inverse
   "The set of integers under addition forms a mathematical group";
   - mathematical group
    
4. (astronomy) a small number (up to about fifty) of galaxies that are near each other
   "The Local Group includes our Milky Way and the Andromeda galaxy"

1. Arrange into a group or groups
   "Can you group these shapes together?"
    
2. Form a group or group together
   "The protesters grouped in front of the government building";
   - aggroup [archaic]

Derived forms: grouping, groups, grouped

Type of: abstract entity, abstraction, assemble, assort, building block, class, classify, foregather [formal], forgather, gather, meet, separate, set, sort, sort out, unit

Part of: molecule

Encyclopedia: Group