burden

(noun) an onerous or difficult concern. Synonyms: load, encumbrance, incumbrance, onus. Examples: "The burden of responsibility." "That's a load off my mind."

(noun) weight to be borne or conveyed. Synonyms: load, loading.

(noun) the central meaning or theme of a speech or literary work. Synonyms: effect, essence, core, gist.

(noun) the central idea that is expanded in a document or discourse.

(verb) weight down with a load. Synonyms: burthen, weight, weight down.

(verb) impose a task upon, assign a responsibility to. Synonyms: charge, saddle. Examples: "He charged her with cleaning up all the files over the weekend."