Agency
Part of speech: noun
Definition: The faculty of acting or of exerting power; the state of being in action; action; instrumentality. The office of an agent, or factor; the relation between a principal and his agent; business of one entrusted with the concerns of another. The place of business of an agent. A bond issued by a US government-backed entity, such as Fannie Mae.
Example sentence: Here's what I believe, I think the FBI is the premier law enforcement agency in the history of the world but i think there was some bad apples over there.
Means
Part of speech: noun
Definition: (now chiefly in the plural) A method or course of action used to achieve some result.That by which something is done; a tool, device, or strategy to achieve something; as, a means to an end.Resources; riches; as, a person of means.
Part of speech: verb
Definition: To lament.
Example sentence: To be nobody but yourself in a world which is doing its best, night and day, to make you everybody else - means to fight the hardest battle which any human being can fight; and never stop fighting.