The Collaborative International Dictionary of English v.0.48:

Browser \Brows"er\ (brouz"[~e]r), n.
   1. An animal that browses.
      [1913 Webster]

   2. (Computers) a computer program that permits the user to
      view multiple electronic documents in a flexible sequence
      by the process of activating hypertext "buttons" within
      one document, which serves as a reference to the location
      of related document. The term is currently (late 1990's)
      used mostly for programs which allow traversing hypertext
      paths in documents on the internet. A typical browser will
      permit the user to easily reverse direction, and view
      again documents previously accessed.
      [PJC]

Jargon File (4.4.4, 14 Aug 2003):

browser
 n.

   A program specifically designed to help users view and navigate
   hypertext, on-line documentation, or a database. While this general
   sense has been present in jargon for a long time, the proliferation
of
   browsers for the World Wide Web after 1992 has made it much more
   popular and provided a central or default techspeak meaning of the
   word previously lacking in hacker usage. Nowadays, if someone
mentions
   using a `browser' without qualification, one may assume it is a Web
   browser.