appellations, appeasements
underwhelmed
outrageously
effortlessly
seismography
Bloodcurdling
Trick or Treat is 12 letters but it's 3 words.
Successfully is a 12 letter word with three set of double letters. Stubbornness is another 12 letter word.
Brown recluse is a 12-letter word for a type of spider.
Lighthearted is a 12 letter word. Lithographed is another 12 letter word that starts with L and ends with D.
manufactured
manufactured
That makes no sense