Trick or Treat is 12 letters but it's 3 words.
refreshments is the word
effortlessly
Successfully is a 12 letter word with three set of double letters. Stubbornness is another 12 letter word.
bibliography
gobbledygook
refreshments is the word
underwhelmed
outrageously
effortlessly
appellations, appeasements
seismography
Bloodcurdling
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