onus
词根词缀：
exonerate v. 免除；无罪释放
ex 出 + oner 负担 + ate 做，造成，使… → 从负担中摆脱出来 → 无罪释放
exoneration n. 免除责任；无罪释放
ex 出 + oner 负担 + ation 行为，过程，状态，结果 → 免除责任；无罪释放
onerous adj. 繁重的；费力的
oner 负担 + ous …的 → 繁重的；费力的
onus n. 负担，责任
on 负担 + us 表名词 → 负担，责任
数据来源：新东方英语词汇速记大全
相关例句：
I believe the onus is upon us to vote down the project.
我认为我有责任否决这项工程。
The onus of bringing up five children.
抚养五个孩子的责任。
The onus is on Romney to make an impression.
罗姆尼的责任是给大家留下深刻的印象。
The onus was on me to earn enough to support the family.
挣足够的钱养家活口是我的责任。
Problems existed in nursing work of obstetrics department after enforcement of inversion of onus probandi
举证责任倒置后产科护理工作中存在的问题及对策
Leipziger says the onus is now on all countries to overcome the bottlenecks to striking a deal.
Leipziger表示，现在，所有的发展中国家应负起责任，克服“瓶颈”，以达成协议。