There's more than a few ways.
For a shorter list this could work well:
Set variable 'Word' to choose("apple","orange","banana")
For a longer list you could
1. Create a text file with all the words separated with commas.
2. Add Ajax to the project and add the text file to your project files.
3. On Start of layout -> Ajax Request Wordlist.txt (tag "GetList")
4. Ajax On "GetList" completed -> Set variable 'Word' to tokenat(Ajax.LastData,round(random(tokencount(Ajax.LastData,","))),",")
sorry but how do i do that?