What is the meaning of Standby?

A state of readiness without immediate involvement; remaining in preparation for (a sudden or unforeseen event or situation).

Waiting at the airport in the hope of getting a seat on a flight that is already booked out.

Something that is standard, well-tested, or frequently used.

To wait briefly, as for additional communication by radio or telephone; alternative spelling of stand by

Source: wiktionary.org

See also