Other forms: countdowns
A countdown is counting backwards to the moment of an event. The final countdown, start the countdown, countdown to launch.
It was invented for drama rather than engineering — a 1929 German film used one for a rocket launch, and real rocketry copied it because it worked. It also names any run-up to a date. Note the compound of count and down.
1nouncountdownCounting backwards to the moment of an event.
“The crowd shouted the countdown to midnight, and fireworks lit up the sky at zero.”
countdown is a counting.
Count plus down. The device was popularised by a 1929 German film about a rocket, and real rocketry took it up.
From count + down.
Etymology from Wiktionary, CC BY-SA