speed, swiftness; the condition of being rapid / (physics) A measure of velocity relative to the speed of light / (physics) A measure of the velocity of a particle in a beam relative to the beam's axis

plural of rapidity

comparative form of rapid: more rapid

The characteristic of being rapid.

(archaic, colloquial) Rapidly.

(often in the plural) a rough section of a river or stream which is difficult to navigate due to the swift and turbulent motion of the water. / (dated) A burst of rapid fire.

Very swift or quick. / Steep, changing altitude quickly. (of a slope) / Needing only a brief exposure time. (of a lens, plate, film, etc.) / (England, dialectal) Violent, severe.

plural of rapid

(military, US) Acronym of Real-Time Automated Personnel Identification System.

(of a gun) Able to fire bullets in quick succession. / (of a series of questions, etc.) Delivered in a rapid continuous stream.