Here's something that works if you define things in terms of a Ruby
module in the wordlist.rb file:

wordlist.rb
---------------

module Wordlist

CODE_WORDS = {
   'starmonkeys' => 'Phil and Pete, those prickly chancellors of the
New
Reich',
   'catapult' => 'chucky go-go', 'firebomb' => 'Heat-Assisted Living',
   'Nigeria' => "Ny and Jerry's Dry Cleaning (with Donuts)",
   'Put the kabosh on' => 'Put the cable box on'
 }

end

And then here's the other test file:

wordtest.rb
----------------

require 'wordlist'


 # Get evil idea and swap in code words
 print "Enter your new idea: "
 idea = gets
 Wordlist::CODE_WORDS.each do |real, code|
   idea.gsub!( real, code )
 end


 # Save the jibberish to a new file
 print "File encoded.  Please enter a name for this idea: "
 idea_name = gets.strip
 File::open( "idea-" + idea_name + ".txt", "w" ) do |f|
   f << idea 
 end