documentary       
 noun [ C ] uk/ˌdɒk.jəˈmen.tər.i/ us/ˌdɑː.kjəˈmen.t̬ɚ.i/
B1 (电影或电视)纪录片;纪实性广播节目
a film or television or radio programme that gives facts and information about a subject
  The documentary took a fresh look at the life of Darwin. 这部纪录片从一个崭新的角度介绍了达尔文的一生。 
 They showed a documentary on animal communication. 他们放映了一部关于动物之间交流沟通的纪录片。 
 - More examples
 - We're compiling some facts and figures for a documentary on the subject.
 - The documentary was made on location in the Gobi desert.
 - The documentary presented us with a balanced view of the issue.
 - The documentary went through all the graphic details of the operation in unsparing detail.
 - The documentary was a misrepresentation of the truth and bore little resemblance to actual events.
 
documentary          
adjective [ before noun ] uk/ˌdɒk.jəˈmen.tər.i/ us/ˌdɑː.kjəˈmen.t̬ɚ.i/
 文件的;文书的
in the form of documents
  Human rights campaigners have discovered documentary evidence of torture. 人权活动家们已经发现了刑讯逼供的书面证据。 
  (电影、电视、广播节目等的)纪实的,记录的
giving facts and information about a subject in the form of a film or television or radio programme
  Most of her movies have a documentary style. 她的电影大多是纪实风格的。