Definitions of group:

• noun:   any number of entities (members) considered as a unit
• noun:   a set that is closed, associative, has an identity element and every element has an inverse
• noun:   (chemistry) two or more atoms bound together as a single unit and forming part of a molecule
• verb:   arrange into a group or groups

  Example: "Can you group these shapes together?"

• verb:   form a group or group together