Swoop

Verb

 * 1) to fly or glide downwards suddenly; to plunge (in the air) or nosedive
 * 2) to move swiftly, as if with a sweeping movement, especially to attack something

Noun

 * 1) an instance, or the act of suddenly plunging downward
 * 2) an act of rushedly doing something
 * Fortune's a right whore. If she give ought, she deals it in small parcels, that she may take away all at one swoop. – John Webster
 * 1)  passing quickly from one note to the next

Thesaurus
belly buster, belly flop, belly whopper, blow, cannonball, cascade, cataract, chute, collapse, come down, comedown, crash, crash dive, debacle, declension, declination, defluxion, descend, descending, descension, descent, dip down, dive, down, downbend, downcome, downcurve, downfall, downflow, downgrade, downpour, downrush, downtrend, downturn, downward trend, drop, drop down, drop off, dropping, fall, fall down, fall off, falling, gainer, go down, go downhill, gravitate, gravitation, header, inclination, jackknife, lose altitude, nose dive, nose-dive, parachute, parachute jump, pitch, plop, plummet, plummeting, plump, plunge, plunk, pounce, pounce on, pounce upon, pour down, power dive, precipitate, rain, rapids, running dive, rush, skin-dive, sky dive, sky-dive, sound, stationary dive, stoop, stroke, swan dive, sweep, swoop down, take a header, trend downward, waterfall