PDF
noun [ C or U ] uk/ˌpiː.diːˈef/ us/ˌpiː.diːˈef/
可移植文件格式;采用可移植文件格式的文件，PDF文件（portable document format的缩写）
abbreviation for portable document format: a system for storing and sending documents between computers that does not allow the contents to be changed, or a document created using this system
a PDF file PDF文件