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

    e.g. When teachers assign homework, students usually feel an obligation to do it...
           老师布置作业时，学生通常认为完成作业是一种义务。
    e.g. Ministers are under no obligation to follow the committee's recommendations.
           部长不必非得听从委员会的建议。

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.

obligation什么意思

    e.g. The United States will do that which is necessary to meet its obligations to its own citizens...
           美国将为自己的公民尽其应尽的义务。
    e.g. I have an ethical and a moral obligation to my client.
           我对我的当事人负有道义上的责任。

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.

    e.g. If you are selling your property, why not call us for a free valuation without obligation?...
           如果您打算出售房产，何不打电话让我们作免费估价呢？
    e.g. You can review your policy in detail for a full 15 days without obligation.
           您可以在15天的免费体验期内仔细审核保单细则。