Definitions of dvr on the Web:

• digital video recorder
  en.wiktionary.org/wiki/DVR

• DVR is so popular these days, a household without one is becoming rare. DVR is a high capacity hard drive embedded in a set–top box. It records video programming from a television set. ...
  www.xinua.com/itvglossary.html

• Diploma in Veterinary Radiology
  www.vetspecialists.co.uk/07_GenContent/Gloss_01.html

• Sometimes called personal video recorders (PVRs), DVRs are hard-drive based recording systems that allow viewers to copy TV programs for later viewing, similar to videocassette recorders. ...
  www.pvt.com/oth/glossary.htm

• An outboard video recorder often supplied by cable TV or satellite TV systems which uses a large-capacity hard drive to record and store video programs, either in Standard Definition or High Definition along with the digital audio surround soundtracks. ...
  www.axiomaudio.com/avglossary.html

• Digital recording hard drives (EG TiVo) which allow viewers to record television programs when they want without video tapes or other removable ...
  itvx.net/2007/09/11/product-placement-glossary/

• Digital Video Recorder. Receivers with a built in hard disk for recording programming with great audio and video quality. The first hard disk receivers were called PVR's.
  2getdtv.com/directv/glossary.html

• A device that records video and stores it onto a hard disk in digital format, eliminating the need for video cassette tapes. ...
  www.alphacardsecurity.com/video-surveillance-glossary.shtml

• A digital video recorder is basically a computer that converts the incoming (analog) signal from the cameras to digital, compresses it, and stores it. The DVR replaces the function of a multiplexor (or quad or switcher) and a security VCR.
  bestsecuritycam.com/index.php