/ˌɑː.bləˈɡeɪ.ʃən/
~ (to do sth) the state of being forced to do sth because it is your duty, or because of a law, etc. 义务；职责；责任
You are under no obligation to buy anything.
你不必非买什么东西不可。
She did not feel under any obligation to tell him the truth.
她觉得没有义务告诉他实情。
I don’t want people coming to see me out of a sense of obligation.
我不想让别人迫于无奈来看我。
We will send you an estimate for the work without obligation (= you do not have to accept it).
我们将寄上工程估算，仅供参考。