From Longman Business Dictionary
responsibilityre·spon·si·bil·i·ty /rɪˌspɒnsəˈbɪlətirɪˌspɑːn-/ noun1[uncountableU] when someone is officially in charge of something and has to make decisions about itresponsibility forIn his new post, he willassume responsibility for all the company’s radio and TV operations.
→ corporate social responsibility2responsibilities [plural] all the things someone is in charge of in a particular job, position etcMy workload and responsibilities have increased more than my salary.
3[uncountableU] blame for something bad that has happenedresponsibility forAs chief executive, Iaccept responsibility for certain administrative problems.
Lawyers for the airlinedenied anyresponsibility for the incident.