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.Oxford Collocations DictionaryPDF is used before these nouns: file,formatSeefull entryWord Origin1990s: abbreviation of Portable Document Format.
See PDF in the Oxford Advanced American Dictionary