countdown

As nouns the difference between countdown and timer

is that countdown is a countdown, count(ing) backward to the (starting) time of some event while timer is someone or something which times.

As nouns the difference between timestamp and countdown

is that timestamp is (computing) the date and time at which an event occurred, often included in a log to track the sequence of events while countdown is a countdown, count(ing) backward to the (starting) time of some event.

As a verb timestamp

is (computing) to record the date and time of (an event, etc).

As nouns the difference between alarmclock and countdown

is that alarmclock is while countdown is a countdown, count(ing) backward to the (starting) time of some event.

As nouns the difference between countdown and kis

is that countdown is a countdown, count(ing) backward to the (starting) time of some event while kis is .

As nouns the difference between countdown and offspring

is that countdown is a countdown, count(ing) backward to the (starting) time of some event while offspring is a person's daughter(s) and/or son(s); a person's children.

As nouns the difference between countdown and mountdown

is that countdown is a countdown, count(ing) backward to the (starting) time of some event while mountdown is the act of mounting an electrical component onto a surface.

As nouns the difference between countdown and prestart

is that countdown is a count backward in fixed units to the time of some event, especially the launch of a space vehicle while prestart is the countdown immediately before the start of a race.

As a verb countdown

is to count down.

As an adjective prestart is

prior to the beginning of a race.