n.

1. （道义上或法律上的）义务；责任[C][U][（+to）][+to-v]
   We were under obligation to finish the work in a satisfactory way.

   我们有义务圆满地完成工作。

   You are under no obligation to buy the house if you have not signed a purchase agreement.

   如果你没有签订购买合同，就不一定非买这房子不可。

   Our parents fulfilled their obligation to support us.

   父母亲尽到了抚养我们的责任。

2. 恩惠[C][（+to/toward）]
   repay an obligation

   报答恩惠

3. 合约，契约；证券[C]
   The builder failed to fulfil the terms of his obligation.

   营造商未能履行合同的条款。

4. 偿付债务的款项[C]
   The lawyer drew up a legal paper discharging him from all obligations.

   律师拟定了一份法律文件，免除他所有的债务款项。

n.

1. an act or course of action to which a person is morally or legally bound.
   ▸the condition of being so bound.
2. a debt of gratitude for a service or favour.