standby
🇺🇸
/ˈstændbaɪ/
🇬🇧
/ˈstændbaɪ/
A person or thing ready to be used if needed.
Keep this flashlight as a standby in case the power goes out.
把这个手电筒作为备用,以防断电。
Available only at the last minute, not in advance.
She bought a standby ticket just before the flight departed.
她在航班起飞前最后一刻买了一张候补票。