countdown

American  

[kount-doun] / ˈkaʊntˌdaʊn /

noun

1. the backward counting in fixed time units from the initiation of a project, as a rocket launching, with the moment of firing designated as zero.

2. the final preparations made during this period.

3. a period of increasing activity, tension, or anxiety, as before a deadline.

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countdown British  

/ ˈkaʊntˌdaʊn /

noun

1. the act of counting backwards to time a critical operation exactly, such as the launching of a rocket or the detonation of explosives

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verb

1. to count numbers backwards towards zero, esp in timing such a critical operation

Etymology

Origin of countdown

1950–55, noun use of verb phrase count down

Example Sentences

Throughout a countdown the launch weather officer must be clear and convinced that none of the weather criteria are violated in order to give the weather 'go' call for launch.

From BBC • Mar. 30, 2026

With the Bacon triptych up, the new David Geffen Galleries continue the countdown to their grand public opening on May 4.

From Los Angeles Times • Mar. 17, 2026

Lamenting the logistical nightmare, exorbitant costs and strain on working families, they offer tips and tricks for locking in sought-after sessions: Pay attention to countdown clocks.

From The Wall Street Journal • Mar. 15, 2026

That 20-day deadline was put on hold by the appeals court, but presumably the countdown has resumed — or is about to.

From Los Angeles Times • Mar. 3, 2026

We went through our countdown and I turned the firing switch.

From "October Sky" by Homer Hickam