(dance, music) A dance at a concert where participants mosh in a circular path, leaving the centre clear.

A social circle on the Internet.

plural of e-circle

plural of hour circle

(astronomy) The great circle through an object whose location is to be determined and the two celestial poles.

A phenomenon that occurs on rivers during winter, where floating ice caught in an eddying flow will rotate around, knocking off its distant edges, forming a floating revolving circular disk, slowing turning under the influence of the underlying vortex current; when the temperature conditions are not too warm, leading to ice breakup and fragility, and not too cool, freezing over the entire surface.

(of a black hole) Synonym of photon sphere

celestial equator

(algebra) The group of all complex numbers of unit modulus, with the group operation being complex multiplication.

plural of generalized circle