Used to slow down an object or being that is moving.
Used by Dumbledore to save Harry Potter from a fall in the film version of Harry Potter and the Prisoner of Azkaban.
 Possible Etymology
Likely the combination of two words; the Anglo-French arester, meaning "To bring to a stop", and the Latin Momentum, meaning "The force or strength gained whilst moving." Literal translation: "Bring its momentum to a stop."