top dead center

Noun

 * 1)  A position in the four-stroke combustion process wherein the piston is at the topmost point in its stroke. This can either be during the compression phase or the combustion phase.
 * 2)  The reference mark on a flywheel (and engine block) indicating the engine is in the top dead center position, when aligned.

Translations

 * Finnish:
 * Spanish: punto muerto superior