PDF

Từ điển Oxford Advanced Learner 8th

PDF 7 BrE [ˌpiː diː ˈef] NAmE [ˌpiː diː ˈef] (also ˌPDˈF file) noun (computing)
the abbreviation for ‘Portable Document Format ’ (a type of computer file that can contain words or pictures. It can be read using any system, can be sent from one computer to another, and will look the same on any computer.)
•I'll send it to you as a PDF.

Word Origin:
[PDF] 1990s: abbreviation of Portable Document Format.