from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Of a scene shot while advancing the film in the camera more slowly than it will play on screen. This results in speeding up the action in the final film.
- v. Simple past tense and past participle of undercrank.
From under + crank; dating from a time when movie film was advanced in a camera by the turning of a crank. (Wiktionary)