The length of time for which something exists or is current or valid.
The length of time for which an organism lives.
Some clams have lifespans far longer than those of human beings.
The time when something happens.
The synchronization of the firing of the spark plugs in an internal combustion engine.
The regulation of the pace of e.g. an athletic race, the speed of an engine, the delivery of a joke, or the occurrence of a series of events.
An instance of recording the time of something.