[SQL, regex, words] how to match word boundaries using regex's?

Hi,

I have been searching all the mailing lists, the on-line
docs, and the source! but cannot find an answer/solution to
this:

I have a varchar() field containing descriptions of things
(doesn't matter what they are).

I want to do a regex match limited to words.

I tried this:

   where ... ~ '\Wword\W';
   where ... ~ '\W*word\W*';
   where ... ~ '\b\(word\)\b';

and other things with LIKE but no joy.

How can I do this?

thanks
tony