back 1. (n.) opposite of front 背面
[例] Please sign the cheque on the back.
[同义词] rear, reverse
2. (adj.) from the past 过去的、拖欠的
[例] We have a lot of back orders.
3. (v.) support 资助
[例] The bank backed my new venture.
[同义词] support, encourage
backdate (v.) to put a date on a document that is earlier than the real date, so that it is valid from that earlier date 倒填日期
[例] He backdated the bill so that it can be valid.
back order (n.) an order for goods that have not yet been produced or supplied 积压定单
[例] After a long vacation, I found myself in a huge stack of back orders.
back out (v.) to give up or not do something after agreeing to do it 不履行
[例] You will be charged for sure if you back out of the contract.
backer (n.) person who supports financially 资助者
[例] The company has some big backers.
[同义词] patron, sponsor, benefactor
backing (n.) support, usually financial one 资助
[例] Strong governmental baking makes the project very profitable.
backhander (n. inf.) a bribe, money given under the table 贿赂
[例] The chief director was arrested for his involvement in some backhander affairs.
backlog (n.) build-up of work or orders which have not been processed 积压的工作（或订单）
[例] The failure of the project was due to backlog of superior orders.
back up (v.) support 支持
[例] You should back up all claims you make.
back-up( back up ) (n. & v.) to make a cope in case the original one is lost or damaged 备份
[例] I made a back-up of that document in case of some unforeseen damage to it.