2016 is almost over, so here is an appropriate 'What is a Word' puzzle.
If a word conforms to a special rule, I call it a Final Word™.
Use the following examples below to find the rule.
|Final Words ™||Not Final Words ™|
And, if you want to analyze, here is a CSV version:
Final Words™,Not Final Words™ ANGEL,DEVIL CHILDREN,PARENTS EARTH,SPACE FURLONGS,FEET GROUND,AIR OVER,UNDER PERPLEXED,ASTONISHED SKIRT,DRESS THRICE,TWICE TOGETHER,ALONE TWELVE,THIRTEEN YOU,WE
The puzzle satisfies the series' inbuilt assumption, that each word can be tested for whether it is a Final Word™ without relying on the other words.
These are not the only examples of Final Words™; many more exist.
What is the special rule these words conform to?
All Final Words™ have been in use for a long, long time.