standbyunit
nounUK /ˈstændbaɪ ˈjuːnɪt/
US /ˈstændbaɪ ˈjuːnɪt/
A standby unit is a spare thing that is ready to be used if the main one stops working.
The hospital keeps a standby unit in case the main generator fails.
RELATED WORDS
OTHER MEANINGS
2. A person or team kept ready to take over a job if needed.
A standby unit of firefighters waited outside the building.
3. A second piece of equipment kept in reserve for immediate use.
The factory's standby unit kicked in when the power went out.
4. A military group held back from the main action, ready to assist.
The commander kept a standby unit near the rear of the formation.