In the Assumption that the words are Text elements…?
It sounds like you want to use persistent-symbols
Remove all the words from last 15 of the scenes.
On the first scene select each word and use the menu Symbol-> New Persistent Symbol from selection.
Make sure you chose add to all Scenes.
This will put the symbol across all scenes.
When you change a word on one scene it will change on all.
There are some caveats with this.
If the Original words elements have any actions on them then these will now be the same action for all.
This can be a problem if each scene needs the action to be different. There are other things that may make this approach a bit difficult but we need more info to get around them if needed.
It may be best to post an example project…