slow motion

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A filmmaking technique in which the action on screen is slower than normal, achieved by filming at a speed faster than the standard rate and then projecting the film at the standard speed.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A technique of film, photography, and video to stretch time and allow visibility of things normally happening too fast to be conveniently examined.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a movie that apparently takes place at a slower than normal speed; achieved by taking the film at a faster rate