When the mechanic revved the engine, a sharp spark knock echoed through the test bay as the fuel-air mixture detonated before the piston reached top dead centre.

After the long hike, she knocked back a bottle of water and sighed with relief.

He kept knocking back espresso shots to stay awake during the night shift.

The sudden cop knock at the door made my heart skip a beat.

Halfway up the climb he felt the hunger knock and had to ease off the pace to recover.

During the boxing match, he knocked out his opponent with a perfectly timed uppercut.

The experienced fighter was knocking out challengers one after another throughout the tournament.

Her knock knees made finding comfortable shoes a constant challenge.

After repeated safety issues, the board voted to knock on the head the plan to expand the factory.

After bragging about his promotion, he couldn't stop knocking wood to avoid jinxing it.