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.
the final preparations made during this period.
a period of increasing activity, tension, or anxiety, as before a deadline.

Origin of countdown

1950–55, Americanism; noun use of verb phrase count down Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for countdown

Contemporary Examples of countdown

Historical Examples of countdown

  • Although attentive, he was not tense, even during the countdown.

  • It was like the countdown for a rocket firing, Rick thought.

    The Flaming Mountain

    Harold Leland Goodwin

  • The next night, the big news was the countdown in process at Canaveral to put a functioning "dome" on the moon.

  • He hoped the launching crew had gotten their fingers frozen off while they were going through the countdown.

    Pushbutton War

    Joseph P. Martino

  • By agreement, the countdown was to be broadcast to all aircraft over one of the airport frequencies.

    The Flaming Mountain

    Harold Leland Goodwin

British Dictionary definitions for countdown



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

verb count down (intr, adverb)

to count numbers backwards towards zero, esp in timing such a critical operation
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for countdown

1953, American English, in early use especially of launches of rockets or missiles, from count (v.) + down.

Online Etymology Dictionary, © 2010 Douglas Harper