|Origin:||swope 'to sweep' (11-19 centuries), from Old English swapan; SWEEP1|
if a bird or aircraft swoops, it moves suddenly down through the air, especially in order to attack something:
The eagle hovered, ready to swoop at any moment.
swoop down/over/across etc
A helicopter suddenly swooped down.
if the police, army etc swoop on a place, they go there without any warning in order to look for someone or something
Drug officers swooped on several addresses in London last night.