/ ˌdɒkjuˈmentri; NAmE ˌdɑːk-/ noun , adjective
■ noun
( pl. -ies ) a film or a radio or television programme giving facts about sth :
a television documentary about / on the future of nuclear power
■ adjective [ only before noun ]
1.
consisting of documents :
documentary evidence / sources / material
2.
giving a record of or report on the facts about sth, especially by using pictures, recordings, etc. of people involved :
a documentary film about the war