noun

1. a number of persons or things gathered closely together and forming a recognizable unit; cluster; aggregation; band a group of houses
2. a collection of objects or figures forming a design or part of a design, as in a work of art
3. a number of persons or things classified together because of common characteristics, community of interests, etc.
4. Chem.
   1. a unit consisting of two or more joined atoms within a molecule; esp., a radical ()
   2. a number of elements with similar properties, forming one of the vertical columns of the periodic table
   3. a number of elements having similar chemical reactions
5. Geol. a stratigraphic unit consisting of two or more formations
6. Math. a closed set of elements having an associative binary operation (usually multiplication), an identity element (I × a = a × I = a), and an inverse element for each element (a × 1/a = 1/a × a = I)
7. ☆ a military aircraft unit; specif., in the U.S. Air Force, a subdivision of a wing, composed of two or more squadrons
8. ☆ U.S. Mil. a unit made up of two or more battalions or squadrons

Etymology: Fr groupe < It gruppo, a knot, lump, group < Gmc *kruppa, round mass: see crop

transitive verb, intransitive verb

adjective