Office 2003 uses the on line proofing tools by default. If you don't have an
Internet connection, or you have a very slow connection, then selecting the
Thesaurus may result in a long delay. (BTW, shortcut for Thesaurus is
Shift+F7 with the selection point anywhere in the word.)
To change this, go to Tools, Options, General tab and select Service
Options, On Line Options and clear the checkboxes.