Source : WordNet®

search engine
     n : a computer program that retrieves documents or files or data
         from a database or from a computer network (especially
         from the internet)

Source : Free On-Line Dictionary of Computing

search engine
     
         A remotely
        accessible program that lets you do keyword searches for
        information on the {Internet}.  There are several types of
        search engine; the search may cover titles of documents,
        {URL}s, headers, or the {full text}.
     
        {A list of search engines
        (http://cuiwww.unige.ch/meta-index.html#MISC)}, Centre
        Universitaire d'Informatique at the University of Geneva
     
        (1995-11-28)