Ran into most words listed above as not valid also. Adding to the list:
Y'all should be thankful hints are ONLY 100 coins. MINE just went up to 200 each!
Y'all should hush & be thankful...
Around level 780, I realized MY hints cost 200 coins!
It WOULD be nice to choose my own avatar.
...mixed feelings labelled a 'tidal wave' 😆🤣😅
🦄🧚🏼♀️ ←way cuter
I ran across "freon" as an unrecognized word also.
Legitimate words are not recognized including "dally," "liber" and others.