What you are wanting to do is really an undertaking. Take this
list of abbreviations for example. It would not be a simple task to build an efficient script to search your text file for a word that matched any of the ones on the list. In my opinion this is where a database would be your friend.
On the other hand if you wanted to only look for a few say 30 or so then you could use a hash. Which would be much easier.
Essentially, what you want to do is read the file and split on the whitespace and loop through each for and see if it matches any of the words of your abbreviations list. Have you written any code at this point?
--Kevin