Definitions for "Motion capture"
A way of realistically animating a digital character. A person acts out the basic motions that the animated character is supposed to undergo. The characteristics of the motion, like the gait and the length of the stride, is captured by cameras or special suits and passed on to special software. These characteristics are then be used to animate the character in the animation software.
The technique of studying the movement of real people or objects to create more real character animations in computer games or simulations.
Motion capture is a technique that uses real life movement for use within a computer for such applications as CGI animation. E.g. In the making of Lord of the Rings a human actor (Andy Serkis) acted out the movements for Gollum, these movements were then used within a computer environment to animate the movements of the 3D CGI Gollum.