Source : Webster's Revised Unabridged Dictionary (1913)

Bookmark \Book"mark`\, n.
   Something placed in a book to guide in finding a particular
   page or passage; also, a label in a book to designate the
   owner; a bookplate.

Source : WordNet®

bookmark
     n : a marker (a piece of paper or ribbon) placed between the
         pages of a book to mark the reader's place [syn: {bookmarker}]

Source : Free On-Line Dictionary of Computing

bookmark
     
         A user's reference to a document on the
        {World-Wide Web} or other hypermedia system, usually in the
        form of a {URL} and a title or comment string.
     
        Most World-Wide Web and {Gopher} {browsers} can save and load
        a file of bookmarks to allow you to quickly locate documents
        to which you want to refer again.
     
        (1997-06-09)