A staircase in the form of a helix.

A series of thoughts or actions which feeds back into itself, causing a situation to become progressively worse. It is worse than a vicious circle, which is self-sustaining in its current state.

plural of spiral pass

(sports) A long pass in American football or rugby in which the ball is given a brisk spin (about its longitudinal axis) as it is thrown so that it travels in a smooth arc without tumbling or wobbling.

plural of spiral DRAGN

(astronomy) a spiral galaxy which contains a DRAGN

A Costa Rican tropical plant distantly related to ginger, Costus barbatus, which is grown for its showy red flowerheads.

plural of spiral ginger

plural of Ekman spiral

A structure of currents or winds near a horizontal boundary in which the flow direction rotates as one moves away from the boundary.