A demographic grouping based on age.

(group theory) The projective general linear group mathbf PGL(2,ℂ): the group of Möbius transformations on the Riemann sphere.

Used other than figuratively or idiomatically: see group, theory; a theory about (particular kinds of) groups.

(physics, mathematics) The group of all Lorentz transformations in spacetime.

A group of people joined temporarily to accomplish some task or take part in some organised collective action. / (US military) A component of a naval task force.

In chemistry, a group of elements with related properties similar to that of platinum, notably high resistance to chemical activity, particularly oxidation and reaction with acids. The platinum group consists of the elements ruthenium, rhodium, palladium, osmium, iridium, and platinum. In the periodic table of the elements they are in period 5 or 6 and in groups 8, 9 or 10.

A group of people who identify with one another, especially on the basis of ancestral, national, cultural, historical or religious grounds.

(physics) the propagation velocity of the envelope of a modulated travelling wave, which is considered as the propagation velocity of information or energy contained in it.

(mathematics) the set of rigid motions that are also affine transformations.

(mathematics) The group of all affine transformations of a finite-dimensional vector space.