A situation in which the solution to one problem makes each future problem easier to solve than the original one.

A group of families who share the task of babysitting on a rotational, or other equalising basis.

(idiomatic) To argue a point by repetition of the same theme, sometimes by using different words, but without making any progress.

present participle of talk in circles

Alternative spelling of semicircle

Alternative spelling of circular sector

Synonym of fairy ring / A circular patch barren of vegetation, often encircled by a ring of stimulated grass growth, typically found in regions of arid grassland.

A number of close friends who usually do things together as a group.

(mathematics, for any point on a curve) The circle that has the same tangent, and the same curvature at the point on the curve.

To draw a wagon train into a circle to allow the wagons to provide cover when under attack. / (idiomatic) To prepare to defend against an attack or criticism.