Definitions of swoop:

• noun:   a swift descent through the air
• noun:   a very rapid raid
• noun:   (music) rapid sliding up or down the musical scale

  Example: "The violinist was indulgent with his swoops and slides"

• verb:   move with a sweep, or in a swooping arc
• verb:   seize or catch with a swooping motion
• verb:   move down on as if in an attack

  Example: "The raptor swooped down on its prey"