名词

1. 义务;责任
If you have an obligation to do something, it is your duty to do that thing.

2. (照顾某人或保护某人利益的)义务，责任
If you have an obligation to a person, it is your duty to look after them or protect their interests.

3. (广告中产品或服务)免费试用地，免费体验地
In advertisements, if a product or a service is available without obligation, you do not have to pay for that product or service until you have tried it and are satisfied with it.