🎯 Exact middle ⚙️ Crank position

dead center

1 8.2

A position where the piston and rod are straight so the engine cannot turn

noun
/dɛd ˈsɛntər/

Specialized

: punto muerto

You should avoid stopping the flywheel at dead center to ensure smooth restarting.
at top dead center

Examples

Make sure the piston is at dead center before starting.
The mechanic explained that starting the engine at dead center can be difficult.
When the piston is at dead center, the engine cannot produce any rotational force.
The crank is at dead center.
The mechanic adjusted the crankshaft to ensure it was at dead center for optimal performance.
To maximize efficiency, the engineer set the flywheel at dead center during the assembly process.
In the animation, the gear rotates smoothly only when the handle is positioned at dead center.

Surface Forms

dead center singular

dead centers plural

Morphology

dead + center

The phrase combines 'dead' used as an intensifier meaning completely/exactly with 'center' meaning the middle point, so the overall sense 'exactly in the middle' is directly derivable from its parts. This compositional intensifier + noun pattern is predictable and common, so a B1 learner who knows both words would understand the MWE.

Etymology

Dead center comes from engines: when the engine's moving parts line up exactly, they are dead (not able to move) at the center, so the engine cannot turn.