Politics.
Dirty
Car
Trips
Airports
Runways.
PAPI
https://en.m.wikipedia.org/wiki/Precision_approach_path_indicator
Radar
Radar is has no connection with PAPI lights.
Doppler
It is part of airport and so does the Radar
Waves
The theme of the game is to connect with last word. Not with the chain or part of the chain. Hence word Radar do not qualify to follow PAPI lights.
Electromagnetic
Current.
Past
Memories
Joyful
Ride
Smooth
Cvt
Abbreviations are not words that is the theme of game.A word is exepted with characteristic similar as below: