Read the dictionary definition of burden. All definitions for this word.
1. weight to be borne or conveyed
2. an onerous or difficult concern
1. the burden of responsibility
2. that's a load off my mind
3. the central idea that is expanded in a document or discourse
4. the central meaning or theme of a speech or literary work
5. impose a task upon, assign a responsibility to
1. He charged her with cleaning up all the files over the weekend
6. weight down with a load