Source : WordNet®

shareware
     n : software that is available free of charge; may be
         distributed for evaluation with a fee requested for
         additional features or a manual etc.

Source : Free On-Line Dictionary of Computing

shareware
     
         /sheir'weir/ {Software} that, like {freeware}, can
        be usually obtained ({download}ed) and redistributed for free,
        but most often is under {copyright} and does legally require a
        payment in the {EULA}, at least beyond the {evaluation} period
        or for commercial applications.  This payment, as well as
        fulfilling the {user}'s legal obligations, may buy additional
        support, documentation, or functionality.  Generally, {source
        code} for shareware programs is not available.  Shareware is
        sometimes also {nagware} and/or {crippleware}, which muddles
        the term and is frowned upon in the community.
     
        See also {careware}, {charityware}, {guiltware},
        {postcardware}, and {-ware}; compare {payware}.
     
        {The History of Shareware
        (http://www.pslweb.com/history.htm)}.
     
        [{Jargon File}]
     
        (2002-01-30)