备用

• Pinyin: bèi yòng
• Hanzi breakdown: 备 = 夂 + 田 + 用 (to prepare); 用 = use pictograph

Meaning

Spare; backup; reserve. Kept ready for use when needed.

Describes items or resources kept in reserve for emergencies or when primary options fail. Common collocations include 备用钥匙 (spare key), 备用电源 (backup power), 备用方案 (backup plan).

Examples

1. 出门记得带备用钥匙，万一锁在外面就麻烦了。 Remember to bring a spare key when you go out — you'll be in trouble if you get locked out.
2. 这台服务器是备用的，主服务器出问题时自动切换。 This server is a backup that automatically takes over if the main server has problems.
3. 我准备了一个备用方案，以防原计划行不通。 I've prepared a backup plan in case the original doesn't work.

Usage Guide

Context: practical, technical, planning

Tone: practical

Do Say

• 你有备用电池吗？(Do you have a spare battery?)
• 这是备用方案。(This is the backup plan.)

Don't Say

• 把主要的说成'备用的' (Don't call the primary thing 备用 — that word specifically means secondary/reserve)

Origin & History

备 (to prepare) + 用 (to use). Prepared for use when needed.

Cultural Context

Generation: All ages

Social background: Universal