An alternate solution to the merriam-webster online dictionary is to use dictd (http://www.dictd.org
). Depending on your distro this should be available for install. You can pick the dictionaries you want to use but this does have a Webster's Revised Unabridged Dictionary (1913) available. There are various clients available for this both command-line and GUI. This will enable you to have a dictionary available to you at all times, whether online or offline.