Meaning

• A number of things or persons being in some relation to one another.

  "A group of people gathered in front of the Parliament to demonstrate against the Prime Minister's proposals."

• A set with an associative binary operation, under which there exists an identity element, and such that each element has an inverse.

• An effective divisor on a curve.

• A (usually small) group of people who perform music together.

  "Did you see the new jazz group?"

• A small number (up to about fifty) of galaxies that are near each other.

• A column in the periodic table of chemical elements.

• A functional group.

  "Nitro is an electron-withdrawing group."

• A subset of a culture or of a society.

• An air force formation.

• A collection of formations or rock strata.

• A number of users with same rights with respect to accession, modification, and execution of files, computers and peripherals.

• An element of an espresso machine from which hot water pours into the portafilter.

• A number of eighth, sixteenth, etc., notes joined at the stems; sometimes rather indefinitely applied to any ornament made up of a few short notes.

• A set of teams playing each other in the same division, while not during the same period playing any teams that belong to other sets in the division.

• A commercial organization.

Meaning

• To put together to form a group.

  "group the dogs by hair colour"

• To come together to form a group.