柯林斯词典

1. N-VAR Backup consists of extra equipment, resources, or people that you can get help or support from if necessary. 後備 (設備、物資或人力)
There is no emergency back-up immediately available. 沒有立即就能獲得的後備。
2. N-VAR If you have something such as a second piece of equipment or set of plans as backup, you have arranged for them to be available for use in case the first one does not work. 備用物 (如設備、計劃)
Every part of the system has a backup. 這套系統的每個部分都有備件。
3. N-COUNT The backup of a song is the music that is sung or played to accompany the main tune. 伴奏; 伴唱
Sharon also sang backup for Barry Manilow. 莎倫還爲巴裡·馬尼洛唱了伴唱。
4. N-COUNT A backup is the same as a . 後援[美國英語]