documentary

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Consisting of, concerning, or based on documents.
• adjective Presenting facts objectively without editorializing or inserting fictional matter, as in a book or film.
• noun A work, such as a film or television program, presenting political, social, or historical subject matter in a factual and informative manner and often consisting of actual news films or interviews accompanied by narration.

from The Century Dictionary.

• Educational; instructional.
• Pertaining to or derived from documents; consisting in documents.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Pertaining to written evidence; contained or certified in writing.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective of, related to, or based on documents.
• adjective which serves to document (record and:or illustrate) a subject.
• adjective of a film presented objectively without the insertion of fictional matter.
• noun A film, TV program, publication etc. which presents a social, political, scientific or historical subject in a factual or informative manner.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective emphasizing or expressing things as perceived without distortion of personal feelings, insertion of fictional matter, or interpretation
• adjective relating to or consisting of or derived from documents
• noun a film or TV program presenting the facts about a person or event