Noun:
1: group, grouping any number of entities (members) considered as a unit
2: chemical group, radical, group (chemistry) two or more atoms bound together as a single unit and forming part of a molecule
3: group, mathematical group a set that is closed, associative, has an identity element and every element has an inverse
Verb:
1: group arrange into a group or groups; "Can you group these shapes together?"
2: group, aggroup form a group or group together