Definitions
1.verbTo announce the passage of time to a precisely timed expected event."The sound system counted down the seconds to meteor impact."
2.verbTo await a precisely timed expected event."The party was counting down the days to Inauguration."
3.nounA count backward in fixed units to the time of some event, especially the launch of a space vehicle.
4.nounThe acts of preparation carried out during this period.
5.nounA radio or television program counting down the top songs of a given week, usually in reverse order ending with the No. 1.