standby

(noun, adjective, verb)

adjective

1. ready for emergency use

- a standby generator

- a standby crew

Similar word(s): secondary

noun

1. something that can be relied on when needed

Definition categories: man–made, thing

2. an actor able to replace a regular performer when required

Similar word(s): understudy

Definition categories: person, actor, histrion, player, thespian

Sentences with standby as a noun:

- The troops were on standby in case of an attack.

- That recipe is an old standby, and she keeps the ingredients around in case of unexpected guests.