As used in this chapter, unless the context otherwise requires:
1. An indictment is an accusation in writing, presented by a grand jury to a competent court, charging a person with a public offense.
2. A presentment is an informal statement in writing, by the grand jury, representing to the court that a public offense has been committed, which is triable within the district, and that there is reasonable ground for believing that a particular person, named or described, has committed it.