Word: 备用 (bèiyòng) Traditional: 備用 备用 dictionary entry bèiyòng reserve; spare; alternate; backup Full dictionary entry for 备用 Example sentences using 备用 2 sentences, showing page 1 of 1. 这把备用钥匙放在哪儿了？ Zhè bǎ bèiyòng yàoshi fàng zài nǎr le? Where did you put the spare key? 重要的文件最好多存一份备用。 Zhòngyào de wénjiàn zuìhǎo duō cún yífèn bèiyòng. It's best to keep a backup copy of important files.